Polysiloxane-polyoxyalkylene block copolymers

ABSTRACT

Polyoxyalkylene polyether admixtures and polysiloxane-polyoxyalkylene block copolymers, a solventless process for producing said copolymers using said admixtures, a process for producing flexible polyether polyurethane foam using said copolymers as foam stabilizers and the foam produced thereby.

This application is a divisional of U.S. application Ser. No. 507,998filed Sept. 20, 1974, now U.S. Pat. No. 3,980,688.

BACKGROUND OF THE INVENTION

Polysiloxane-polyoxyalkylene block copolymers have found wide acceptanceas foam stabilizers in the production of polyurethane foam. Such blockcopolymers include those copolymers whereby the polysiloxane andpolyoxyalkylene blocks are linked by hydrolytically unstablesilicon-oxygen-carbon bonds which copolymers are often referred to ashydrolyzable polysiloxane-polyoxyalkylene block copolymers, as well asthose copolymers whereby said blocks are linked by hydrolytically stablesilicon-carbon bonds, which copolymers are often referred to asnon-hydrolyzable polysiloxane-polyoxyalkylene block copolymers.

Hydrolyzable polysiloxane-polyoxyalkylene block copolymers can beprepared by a variety of common chemical reactions, e.g. by reacting alinear polyoxyalkylene polymer (polyether) whose linear chain is endblocked at one end by a hydroxyl group and at the other end by analkoxy, aryloxy, or aralkyloxy group, with a polysiloxane containing asilanic hydrogen, an alkoxy radical, an amino radical, or a halogen atomdirectly attached to a silicon atom of the polysiloxane, as shown e.g.by the following skeletal equations:

    .tbd. SiOCH.sub.3 + HOC.tbd. ⃡.tbd. SiOC.tbd. + CH.sub.3 OH

    .tbd. SiH+ HOC.tbd. →.tbd. SiOC.tbd. + H.sub.2

    .tbd. SiCl+ HOC.tbd. ⃡.tbd. SiOC.tbd. + HCl

    .tbd. SiN(CH.sub.3).sub.2 + HOC.tbd. →.tbd. SiOC.tbd. + HN(CH.sub.3).sub.2

Non-hydrolyzable polysiloxane-polyoxyalkylene block copolymers areusually prepared by the platinum catalyzed addition reaction of asiloxane containing silanic hydrogen with a linear polyoxyalkylenepolymer (polyether) whose linear chain is end blocked at one end by analkenyloxy group (e.g. allyloxy) and at the other end by an alkoxy,aryloxy, aralkyloxy, or an acyloxy group, as shown e.g. by the followingskeletal equation:

    .tbd. SiH+ H.sub.2 C=CHCH.sub.2 OC.tbd. →.tbd. SiCH.sub.2 CH.sub.2 CH.sub.2 OC.tbd.

thus, polysiloxane-polyoxyalkylene block copolymers in general arenormally prepared by mixing the polysiloxane and polyoxyalkylenereactants in the presence of a solvent and a catalyst, effecting therequired chemical reaction, neutralizing the catalyst, removing thesolvent, and filtering. Of course, it is understood that reactions whichproduce a by-product that is in equilibrium with the desired product andreactants must be driven to completion. For example, a compound such asan organic amine may be added to react with the hydrogen chlorideproduced by the reaction of a polyoxyalkylene alcohol with achlorosiloxane as shown above, while the methanol produced by thereaction of a polyoxyalkylene alcohol with a methoxy-siloxane as shownabove, may be removed by distillation. The employment of a solventincreases the cost of the operation to produce suitablepolysiloxane-polyoxyalkylene block copolymer foam stabilizers forpolyurethane foam: by reducing the amount of block copolymer that can beprepared per batch in a given reactor; by increasing the time requiredto prepare a batch of the block copolymer by the time required to removethe solvent; and by adding the cost of the solvent to the raw materialcost of the block copolymer. It is quite obviously desirable then to beable to reduce or eliminate the required use of a solvent in theproduction of suitable polysiloxane-polyoxyalkylene block copolymer foamstabilizers for polyurethane foam.

Moreover, it is also well known that both the polysiloxane blocks andthe polyoxyalkylene blocks of polysiloxane-polyoxyalkylene blockcopolymers employed as foam stabilizing agents for polyurethane foam arecomprised of a mixture of molecular species. The polysiloxane blocks(e.g., polydimethylsiloxane) have species distributed by molecularweight, by the number of coupling sites in a molecule and by theposition of the coupling sites in a molecule, while polyoxyalkyleneblocks (e.g. polyoxyethylene-oxypropylene) have species distributed bymolecular weight and by the proportion of ethylene oxide and propyleneoxide units within a molecule. The polysiloxane-polyoxyalkylene blockcopolymers then have polyoxyalkylene blocks representing variousmolecules in the mixture distributed on different polysiloxanemolecules.

SUMMARY OF THE INVENTION

It has now been surprisingly discovered that the distribution of themolecular species of the polysiloxane-polyoxyalkylene block copolymershas a definite effect on the polysiloxane-polyoxyalkylene blockcopolymers performance as a foam stabilizing agent.

Therefore it is an object of this invention to provide a novel admixtureof polyoxyalkylene copolymers. Another object of this invention is toprovide novel polysiloxane-polyoxyalkylene block copolymers derived fromthe above-mentioned novel admixture of polyoxyalkylene copolymers and toprovide a novel solventless process for producing suchpolysiloxane-polyoxyalkylene block copolymers. Still another object ofthis invention is to provide a process for producing polyurethane foamsemploying such novel polysiloxane-polyoxyalkylene block copolymers asfoam stabilizers, and to provide polyurethane foam products producedthereby. Other objects and advantages of this invention will becomereadily apparent from the following description and appended claims.

Accordingly, this invention provides as novel compositions of matter anadmixture consisting essentially of from about 20 to about 80 percent byweight of component (A) and from about 80 to about 20 percent by weightof component (B), said percentages being based on the total weight ofcomponents (A) and (B) present in the admixture, wherein component (A)represents low molecular weight polyoxyalkylene polyether, saidpolyether being selected from the class consisting of (i) apolyoxyalkylene copolymer having an average molecular weight in therange of from about 800 to about 2300 wherein about 20 to about 60weight percent of the oxyalkylene groups of said copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,and (ii) a blend of at least two polyoxyalkylene copolymers havingdifferent average molecular weights in the range of from about 500 toabout 2900 and wherein about 20 to about 60 weight percent of theoxyalkylene groups of the copolymers in said blend are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, with the provisothat said blend has an average molecular weight in the range of fromabout 800 to about 2300; and wherein component (B) represents highmolecular weight polyoxyalkylene polyether, said polyether beingselected from the class consisting of (i) a polyoxalkylene copolymerhaving an average molecular weight in the range of from about 3400 toabout 5500, wherein about 20 to about 60 weight percent of theoxyalkylene groups of said copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, and (ii) a blend of at leasttwo polyoxyalkylene copolymers having different average molecularweights in the range of from about 3000 to about 5500 and wherein about20 to about 60 weight percent of the oxyalkylene groups of thecopolymers in said blend are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene, with the proviso that said blendhas an average molecular weight in the range from about 3400 to 5500,and wherein the polyoxyalkylene copolymers of (A) and (B) containterminal groups selected from the class consisting of hydroxy andalkenyloxy at one end of the copolymer and terminal groups selected fromthe class consisting of alkoxy, aryloxy and aralkyloxy at the other endof the copolymer, with the proviso that when the copolymer contains aterminal alkenyloxy group at one end, the terminal group at the otherend of the copolymer can also be acyloxy; with the added proviso thatsaid admixture of (A) and (B) has an average molecular weight in therange of about 1600 to about 2900.

The novel polysiloxane-polyoxyalkylene block copolymers of thisinvention consist essentially of from about 15 to about 35 percent byweight of polysiloxane blocks and from about 85 to about 65 percent byweight of polyoxyalkylene blocks, and further consist essentially ofsiloxy units of the formula R₂ SiO, siloxy units selected from the groupconsisting of those of the formulas (R)(Q)SiO and RSiO3/2 and terminalsiloxy units selected from the class consisting of those of the formulasR₃ SiO1/2 and (R₂)(Q)SiO1/2, wherein the average number of total siloxyunits per molecule of the polysiloxane-polyoxyalkylene block copolymerranges from about 20 to about 200, wherein from about 6 to about 15percent of said total siloxy units are selected from the groupconsisting of (R)(Q)SiO and (R₂)(Q)SiO1/2 and wherein there are no morethan about four RSiO3/2 siloxy units per average polysiloxane molecule,wherein each R individually represents a monovalent hydrocarbon radicalor a substituted monovalent hydrocarbon radical, said radicals beingfree from aliphatic multiple carbon to carbon bonds, and wherein each Qindividually represents a polyoxyalkylene polyether block having theformula -MX wherein each X is a bridging group individually selectedfrom the class consisting of --O-- and --C_(n) H_(2n) O-- wherein n hasa value of 2 or 3, and X is a polyoxyalkylene radical consistingessentially of an admixture of Units A and B of the formula (C₂ H₄O)_(x) (C₃ H₆ O)_(y) Z wherein Z is a terminal group selected from theclass consisting of alkyl, aryl and aralkyl radicals, with the provisothat when M is --C_(n) H_(2n) O-- as defined above, Z can also be aterminal acyl radical, the values of x and y being determined by thefollowing conditions prevailing for Units A and B;

Unit A representing from about 20 to about 80 percent by weight of lowmolecular weight polyoxalkylene polyether based on the total weight ofUnits A and B in said admixture; said polyether being selected from theclass consisting of (i) a polyoxyalkylene copolymer having an averagemolecular weight in the range of from about 800 to about 2300 whereinabout 20 to about 60 weight percent of the oxyalkylene groups of saidcopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, and (ii) a blend of at least two polyoxyalkylenecopolymers having different average molecular weights in the range offrom about 500 to about 2900 and wherein about 20 to about 60 weightpercent of the oxyalkylene groups of the copolymers in said blend areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,with the proviso that said blend has an average molecular weight in therange of from about 800 to about 2300; and

Unit B representing from about 80 to about 20 percent by weight of highmolecular weight polyoxyalkylene polyether based on the total weight ofUnits A and B in said admixture said polyether being selected from theclass consisting of (i) a polyoxyalkylene copolymer having an averagemolecular weight in the range of from about 3400 to about 5500 whereinabout 20 to about 60 weight percent of the oxyalkylene groups of saidcopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, and (ii) a blend of at least two polyoxyalkylenecopolymers having different average molecular weights in the range offrom about 3000 to about 5500 and wherein about 20 to about 60 weightpercent of the oxyalkylene groups of the copolymers in said blend areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,with the proviso that said blend has an average molecular weight in therange of from about 3400 to about 5500; and with the added proviso thatsaid admixture of units A and B has an average molecular weight in therange of from about 1600 to about 2900.

This invention further provides an improved process for producing thenovel polysiloxane-polyoxyalkylene block copolymers as defined above byreacting a polysiloxane polymer with a polyoxyalkylene polyether in thepresence of a catalyst, the improvement which comprises carrying out theprocess in the absence of a solvent and employing as the polyoxyalkylenepolyether composition of matter an admixture consisting essentially offrom about 20 to about 80 percent by weight of component (A) and fromabout 80 to about 20 percent by weight of component (B), saidpercentages being based on the total weight of components (A) and (B)present in the admixture wherein component (A) represents low molecularweight polyoxyalkylene polyether, said polyether being selected from theclass consisting of (i) a polyoxyalkylene copolymer having an averagemolecular weight in the range of from about 800 to about 2300 whereinabout 20 to about 60 weight percent of the oxyalkylene groups of saidcopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, and (ii) a blend of at least two polyoxyalkylenecopolymers having different average molecular weights in the range offrom about 500 to about 2900 and wherein about 20 to about 60 weightpercent of the oxyalkylene groups of the copolymers in said blend areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,with the proviso that said blend has an average molecular weight in therange of from about 800 to about 2300; wherein component (B) representshigh molecular weight polyoxyalkylene polyether, said polyether beingselected from the class consisting of (i) a polyoxyalkylene copolymerhaving an average molecular weight in the range of from about 3400 toabout 5500 wherein about 20 to about 60 weight percent of theoxyalkylene groups of said copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, and (ii) a blend of at leasttwo polyoxyalkylene copolymers having different average molecularweights in the range of from about 3000 to about 5500 and wherein about20 to about 60 weight percent of the oxyalkylene groups of thecopolymers in said blend are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene, with the proviso that said blendhas an average molecular weight in the range of from about 3400 to about5500; and wherein the polyoxyalkylene copolymers of (A) and (B) containterminal groups selected from the class consisting of hydroxy andalkenyloxy at one end of the copolymer and terminal groups selected fromthe class consisting of alkoxy, aryloxy and aralkyloxy at the other endof the copolymer, with the proviso that when the copolymer contains aterminal alkenyloxy group at one end, the terminal group at the otherend of the copolymer can also be acyloxy; and with the added provisothat said admixture of (A) and (B) has an average molecular weight inthe range of from about 1600 to about 2900.

This invention also provides a method for producing a flexible polyetherpolyurethane foam by simultaneously reacting and foaming a mixture of(a) a polyether containing at least two hydroxyl groups per molecule,(b) an organic polyisocyanate, (c) a catalyst for the reaction of (a)and (b) to produce the polyurethane, (d) a blowing agent and (e) a novelpolysiloxane-polyoxyalkylene block copolymer as defined above as a foamstabilizer.

This invention still further provides a flexible polyether polyurethanefoam as produced by the above defined method.

While the use of polyoxyalkylene polyether and mixtures thereof toproduce polysiloxane-polyoxyalkylene block copolymer foam stabilizersfor polyether urethane foam is well known, as pointed out above, suchfoam stabilizers are usually prepared in the presence of a solvent (e.g.toluene) capable of dissolving the polysiloxane and polyoxyalkyleneblocks as seen e.g. by U.S. Pat. Nos. 2,834,748, 3,637,541 and3,801,616. It has now been discovered that excellentpolysiloxane-polyoxyalkylene block copolymer foam stabilizers forflexible polyether polyurethane foam can be prepared in the absence of asolvent by employing as the polyether reactant the above defined noveladmixture of polyoxyalkylene polyethers of this invention. Thisdiscovery is indeed surprising since it is connected to the noveldiscovery that the distribution of the molecular species of thepolysiloxane-polyoxyalkylene block copolymers has a definite effect onthe polysiloxane-polyoxyalkylene block copolymers performance as a foamstabilizing agent for flexible polyether polyurethane foam. Forinstance, polysiloxane-polyoxyalkylene block copolymers produced in theabsence of a solvent polyoxyalkylene polyether having an averagemolecular weight in the range commonly employed for foam stabilizers offlexible polyether polyurethane foam but outside of the scope of abovedefined novel admixture of polyoxyalkylene polyethers of this inventionhave been found to inadequately stabilize flexible polyetherpolyurethane foam or must be used in higher concentrations than those ofthe instant invention.

Thus, the instant invention involves the discovery thatpolysiloxane-polyoxyalkylene block copolymers prepared without a solventrequire a polyoxyalkylene block containing a broad distribution ofmolecular species and that this distribution must contain a significantportion of high molecular weight species in order for said copolymers tofunction as suitable foam stabilizers for flexible polyetherpolyurethane foam.

Accordingly the novel admixtures of polyoxyalkylene polyether of thisinvention as defined above contain several essential features. Forinstance, the admixture must consist of at least two distinctpolyoxyalkylene polyethers having different average molecular weights,i.e., low molecular weight polyoxyalkylene polyether and high molecularweight polyoxyalkylene polyether. Of course, it is obvious that the saidnovel admixture of this invention is not to be misinterpreted asencompassing merely the different species that may constitute apolyoxyalkylene polyether having a specific average molecular weight asproduced. The low molecular weight polyoxyalkylene polyether in saidadmixture must constitute from about 20 to about 80 percent by weight ofsaid admixture based on the total weight of said low and high molecularweight polyoxyalkylene polyethers present in said admixture and musthave an average molecular weight in the range of about 800 to about2300, although it may also consist of a blend of at least two distinctpolyoxyalkylene copolymers having different average molecular weightsthe lowest of which is at least about 500 and the highest of which isabout 2900. Of course, it is understood that the total number ofpolyoxyalkylene copolymers in said blend of low molecular weightpolyoxyalkylene copolymers is immaterial so long as the blend has anaverage molecular weight in the range of about 800 to about 2300. Thehigh molecular weight polyoxyalkylene polyether in said admixture mustconstitute from about 80 to about 20 percent by weight of said admixturebased on the total weight of said low and high molecular weightpolyoxyalkylene polyethers present in said admixture and must have anaverage molecular weight in the range of about 3400 to about 5500,although it may also consist of a blend of at least two distinctpolyoxyalkylene copolymers having different average molecular weightsthe lowest of which is at least about 3000 and the highest of which isat least about 5500. Of course, it is understood that the total numberof polyoxyalkylene copolymers in said blend of high molecular weightpolyoxyalkylene copolymers is immaterial so long as the blend has anaverage molecular weight in the range of about 3400 to about 5500.Moreover the proportions of said low and high molecular weightpolyoxyalkylene polyethers must be such that said novel admixture ofsame has an average molecular weight in the range of from about 1600 toabout 2900 and it should be obvious that the total number of differentlow and high molecular weight polyoxyalkylene polyethers in theadmixture is also immaterial so long as this essential feature is metalong with the other feature defined herein. About 20 to 60 weightpercent of the oxyalkylene groups of the polyoxyalkylene copolymers (bethey low or high molecular weight polyoxyalkylene polyethers) in saidnovel admixture must be oxyethylene, the remainder of the oxyalkylenegroups of said copolymers being oxypropylene. Of course it is to beunderstood that the oxyethylene and oxypropylene groups of saidcopolymers may be present in the polyoxyalkylene block in a random orblock fashion. Finally, the polyoxyalkylene copolymers (be they low orhigh molecular weight polyoxyalkylene polyethers) in said noveladmixture are terminated by terminal or end-blocking groups selectedfrom the class consisting of hydroxy and alkenyloxy (e.g. vinyloxy,allyloxy, and the like) at one end of the copolymer and by terminal orend-blocking groups selected from the class consisting of alkoxy (e.g.methoxy, ethoxy, propoxy, butoxy and the like), aryloxy (e.g. phenoxy,and the like), aralkyloxy (e.g. phenylethoxy, and the like) at the otherend of the copolymer, with the proviso that when the copolymer containsa terminal alkenyloxy group at one end, the terminal group at the otherend of the copolymer can also be acyloxy (e.g. acetoxy, and the like).

The polyoxyalkylene polyether components of the novel admixtures of thisinvention are poly(oxyethylene-oxypropylene) copolymers as pointed outabove. Such copolymers are well known in the art and/or can be producedby any conventional process. For instance, the desired monohydroxyterminated polyoxyalkylene polyethers used in this invention can beprepared by reacting a suitable alcohol with both ethylene oxide andpropylene oxide (1,2-propylene oxide). Suitable alcohols are alkanols,e.g. methanol, ethanol, propanol, isopropanol, butanol, tertiarybutanol, and the like; hydroxy aryl compounds, e.g. phenol, and thelike; hydroxy aralkyl compounds, e.g. 2-phenyl ethanol, and the like;and hydroxy alkenyl compounds, e.g. allyl alcohol and the like. Ingeneral the alcohol starter preferably is placed in an autoclave orother high-pressure vessel along with catalytic amounts of a suitablecatalyst, such as sodium hydroxide, potassium hydroxide, other alkalimetal hyroxides, or sodium or other alkali metals. The ethylene oxideand propylene oxide is then injected into the starter and catalyst and,the reaction being exothermic, the temperature increases, and preferablyis controlled at 70° C. to 120° C. The ethylene oxide and propyleneoxide are preferably premixed and injected together to producecopolymers having oxyethylene and oxypropylene units in randomdistribution, although if desired they may be separately injectedsimultaneously to also produce a random distribution of oxide units orone oxide may be injected to produce an oxide block of desired size andthen the other oxide injected to produce another oxide block of desiredsize. The latter procedure may be repeated to produce more than two suchoxide blocks as desired. Since the oxides are normally gaseousmaterials, pressure is controlled preferably at 50 to 70 p.s.i.g. Theoxides are preferably injected over a period of time until thepoly(oxyethylene-oxypropylene) copolymer of the desired averagemolecular weight size is obtained. The rate of injection can beregulated to help control the pressure and temperature within theautoclave. The proportions of starter and oxide ( as well as thepercentage of ethylene oxide to propylene oxide) used can be varied, asdesired to produce the polyoxyalkylene polyethers of the desired averagemolecular weight. Said percentage and average molecular weight of thepolyoxyalkylene polyethers used in this invention as well as thepreferred embodiments thereof have already been defined above. Ofcourse, it is understood and well known in the art that the resultingpolyethers comprise mixtures of copolymers containing different amountsof combined alkylene oxide and thus have different molecular weightsfrom molecule to molecule and that the formulas of the polyoxyalkylenecopolymers and radicals given herein represent average compositions.

The above-described alcohol-oxide reaction produces a monohydroxyendblocked poly(oxyethylene-oxypropylene) copolymer in which the otherendblocking group is an alkoxy, aryloxy, aralkyloxy, or alkenyloxyradical.

The desired monoalkenyloxy terminated polyoxyalkylene polyethers used inthis invention can be prepared by converting (capping) the hydroxylterminal group of said monohydroxy endblockedpoly(oxyethylene-oxypropylene) copolymers by any conventional means. Forexample, when the monohydroxy terminated copolymer is started with analkanol, hydroxy aryl or hydroxy aralkyl compound the copolymer can bereacted with an alkali metal alkoxide preferably sodium methoxide toproduce the alkali metal alkoxide of the copolymer which is then reactedwith alkenyl halide, preferably a chloride and especially allylchloride, to give the desired monoalkenyloxy endblockedpoly(oxyethylene-oxypropylene) copolymers in which the other endblockinggroup is an alkoxy, aryloxy, or aralkyloxy radical. Alternatively, whenthe monohydroxy terminated copolymer is started with an hydroxy alkenylcompound, the hydroxyl terminal group of the copolymer can be capped inthe same manner using alkyl, aryl or aralkyl halides (preferablychlorides) or by esterifying said hydroxy terminal group with an acyl(preferably acetic anhydride) compound to give the desiredmonoalkenyloxy endblocked poly(oxyethylene-oxypropylene) copolymers inwhich the other endblocking group is an alkoxy, aryloxy, aralkyloxy oracyloxy radical.

Thus the polyoxyalkylene polyethers in the novel admixture of thisinvention may if desired be represented by the average formula:

    Z'O(C.sub.2 H.sub.4 O).sub.x (C.sub.3 H.sub.6 O).sub.y Z

wherein x and y are determined by the above defined average molecularweight of the copolymers and ratio of oxyethylene groups to oxypropylenegroups in the copolymer. Z' is hydrogen or an alkenyl radical and Z isan alkyl, aryl or an aralkyl, radical with the proviso that when Z' isalkenyl, Z can also be an acyl radical. Illustrative examples of suchpolyoxyalkylene polyethers then include those having the averageformulas

    HO(C.sub.2 H.sub.4 O).sub.x (C.sub.3 H.sub.6 O).sub.y CH .sub.3

    ho(c.sub.2 h.sub.4 o).sub.x (C.sub.3 H.sub.6 O).sub.y C.sub.6 H.sub.5

    ho(c.sub.2 h.sub.4 o).sub.x (C.sub.3 H.sub.6 O).sub.y C.sub.2 H.sub.4 C.sub.6 H.sub.5

    h.sub.2 c=ch-ch.sub.2 o-(c.sub.2 h.sub.4 o).sub.x (C.sub.3 H.sub.6 C).sub.y CH .sub.3

    ho-(c.sub.2 h.sub.4 o).sub.x (C.sub.3 H.sub.6 O).sub.y C.sub.4 H.sub.9

    h.sub.2 c=ch-ch.sub.2 o-(c.sub.2 h.sub.4 o).sub.x (C.sub.3 H.sub.6 O).sub.y C.sub.4 H.sub.9

    h.sub.2 c=ch-ch.sub.2 o-(c.sub.2 h.sub.4 o).sub.x (C.sub.3 H.sub.6 O).sub.y C.sub.6 H.sub.5

    h.sub.2 c=ch-o-(c.sub.2 h.sub.4 o).sub.x (C.sub.3 H.sub.6 O).sub.y C.sub.2 H.sub.4 C.sub.6 H.sub.5

    h.sub.2 c=ch-ch.sub.2 o-(c.sub.2 h.sub.4 o).sub.x (C.sub.3 H.sub.6 O).sub.y COCH.sub.3

and the like, where x and y are the same as defined above. Of course, itis to be understood that the novel polyether admixtures of thisinvention can consist of only one type of endblocked polyoxyalkylenecopolymer or any combination of the different types of endblockedpolyoxyalkylene copolymers. Indeed such admixtures can simultaneouslyconsist of both such types of polyoxyalkylene polyethers as themonohydroxy terminated polyoxyalkylene copolymers and the monoalkenyloxyterminated polyoxyalkylene copolymers if desired. Of course, it is to bealso understood that a minor amount of polyoxyalkylene copolymers (bethey low or high molecular weight polyoxyalkylene polyethers) that aresimultaneously terminated at both ends e.g. by the same hydroxy,alkenyloxy, alkoxy, aryloxy, aralkyloxy or acyloxy groups may be presentin said novel admixture due to their possible production in the makingof the desired polyoxyalkylene polyethers or by their deliberateaddition if desired so long as said minor amount of polyoxyalkylenecopolymers does not adversely effect the desired results of the instantinvention.

Accordingly, one preferred class of the novel compositions of matter ofthis invention are admixtures consisting essentially of from about 20 toabout 80 percent by weight (preferably from about 25 to about 50)percent by weight of (A) a low molecular weight polyoxyalkylenecopolymer having an average molecular weight in the range of from about800 to about 2300 (preferably from about 900 to about 1300) whereinabout 20 to about 60 (preferably about 30 to about 55) weight percent ofthe oxyalkylene groups of said copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene; and from about 80 to about20 (preferably from about 75 to about 50) percent by weight of (B) ahigh molecular weight polyoxyalkylene copolymer having an averagemolecular weight in the range of from about 3400 to about 5500(preferably from about 3800 to about 5000), wherein about 20 to about 60(preferably about 30 to about 55) weight percent of the oxyalkylenegroups of said copolymer are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene; and wherein the polyoxyalkylenecopolymers of (A) and (B) contain terminal groups selected from theclass consisting of hydroxy and alkenyloxy at one end of the copolymerand terminal groups selected from the class consisting of alkoxy,aryloxy and aralkyloxy at the other end of the copolymer, with theproviso that when the copolymer contains a terminal alkenyloxy group atone end, the terminal group at the other end of the copolymer can alsobe acyloxy; with the added proviso that said admixture of (A) and (B)has an average molecular weight in the range of from about 1600 to about2900 (preferably about 2000 to about 2400). The preferred terminalgroups are alkenyloxy (especially allyloxy) and alkoxy (especiallybutoxy). Said weight percentages of (A) and (B) are of course based onthe total weight of (A) and (B) present in the admixture.

Another preferred class of novel compositions of matter of thisinvention are admixtures consisting essentially of from about 20 toabout 80 (preferably from about 30 to about 60) percent by weight of (A)a blend of at least two low molecular weight polyoxyalkylene copolymershaving different average molecular weights in the range of about 500 toabout 2900 (preferably at least one of said copolymers has an averagemolecular weight in the range of about 900 to about 1300 and at leastone of said copolymers has an average molecular weight in the range ofabout 1700 to about 2900) and wherein about 20 to about 60 (preferablyabout 30 to about 55) weight percent of the oxyalkylene groups of thecopolymers in said blend are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene, with the proviso that said blendhas an average molecular weight in the range of from about 800 to about2300 (preferably from about 1100 to about 1900 ); and from about 80 toabout 20 (preferably from about 70 to about 40) percent by weight of (B)a high molecular weight polyoxyalkylene copolymer having an averagemolecular weight in the range of from about 3400 to about 5500(preferably from about 3800 to about 5000), wherein about 20 to about 60(preferably from 30 to about 55) weight percent of the oxalkylene groupsof said copolymer are oxethylene, the remainder of the oxalkylene groupsbeing oxypropylene, and wherein the polyoxalkylene copolymers of (A) and(B) contain terminal groups selected from the class consisting ofhydroxy and alkenyloxy (e.g. allyloxy) at one end of the copolymer andterminal groups selected from the class consisting of alkoxy, aryloxyand aralkyloxy at the other end of the copolymer, with the proviso thatwhen the copolymer contains a terminal alkenyloxy group at one end, theterminal group at the other end of the copolymer can also be acyloxy;and with the added proviso that said admixture of (A) and (B) has anaverage molecular weight in the range of from about 1600 to about 2900.Said weight percentages of (A) and (B) are of course based on the totalweight of (A) and (B) present in the admixture.

Still another preferred class of novel compositions of matter of thisinvention are admixtures consisting essentially of from about 20 toabout 80 (preferably from about 30 to about 60) percent by weight of alow molecular weight polyoxyalkylene copolymer having an averagemolecular weight in the range of from about 800 to about 2300(preferably about 900 to about 1300) wherein about 20 to about 60(preferably about 30 to about 55) weight percent of the oxyalkylenegroups of said copolymer are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene; and from about 80 to about 20(preferably from about 70 to about 40) percent by weight of (B) a blendof at least two high molecular weight polyoxyalkylene copolymers havingdifferent average molecular weights in the range of about 3000 to about5500, (preferably at least one of said copolymers has an averagemolecular weight in the range of about 3000 to about 3400 and at leastone of said copolymers has an average molecular weight in the range ofabout 3800 to about 5000), wherein about 20 to about 60 (preferablyabout 30 to about 55) weight percent of the oxyalkylene groups of thecopolymers in said blend are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene, with the proviso that said blendhas an average molecular weight in the range of from about 3400 to about5500 (preferably about 3400 to about 5000) and wherein thepolyoxyalkylene copolymers of (A) and (B) contain terminal groupsselected from the class consisting of hydroxy and alkenyloxy at one endof the copolymer and terminal groups selected from the class consistingof alkoxy, aryloxy and aralkyloxy at the other end of the copolymer,with the proviso that when the copolymer contains a terminal alkenyloxygroup at one end, the terminal group at the other end of the copolymercan also be acyloxy; and with the added proviso that said admixture of(A) and (B) has an average molecular weight in the range of about 1600to about 2900 (preferably about 1600 to about 2600). Said weightpercentages of (A) and (B) are of course based on the total weight of(A) and (B) present in the admixture.

Yet another preferred class of novel compositions of matter of thisinvention are admixtures consisting essentially of from about 20 toabout 80 percent by weight of (A) a blend of at least two low molecularweight polyoxyalkylene copolymers having different average molecularweights in the range of about 500 to about 2900 and wherein about 20 toabout 60 weight percent of the oxyalkylene groups of the copolymers insaid blend are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, with the proviso that said blend has an averagemolecular weight in the range of from about 800 to about 2300; and fromabout 80 to about 20 percent by weight of (B) a blend of at least twohigh molecular weight polyoxyalkylene copolymers having differentaverage molecular weights in the range of about 3000 to about 5500,wherein about 20 to about 60 weight percent of the oxyalkylene groups ofthe copolymers in said blend are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene, with the proviso that said blendhas an average molecular weight in the range of from about 3400 to about5500; and wherein the polyoxyalkylene copolymers of (A) and (B) containterminal groups selected from the class consisting of hydroxy andalkenyloxy at one end of the copolymer and terminal groups selected fromthe class consisting of alkoxy, aryloxy and aralkyloxy at the other endof the copolymer, with the proviso that when the copolymer contains aterminal alkenyloxy group at one end, the terminal group at the otherend of the copolymer can also be acyloxy; and with the added provisothat said admixture of (A) and (B) has an average molecular weight inthe range of about 1600 to about 2900. Said weight percentages of (A)and (B) are of course, based on the total weight of (A) and (B) presentin the admixture.

The method of producing the novel polysiloxane-polyoxyalkylene blockcopolymers of this invention can be conducted in the same manner as anyconventional known method for producing polysiloxane-polyoxyalkyleneblock copolymers such as described e.g. in U.S. Pats. Nos. 2,834,748,2,970,150 and 3,801,616. Such conventional methods have been describedabove and involve the common chemical reactions of reacting thepolyoxyalkylene polyether with a polysiloxane containing a silanichydrogen, an alkoxy radical, an amino radical or a halogen atom directlyattached to a silicon atom of the polysiloxane at elevated temperatures,e.g. from about 60° C. to about 140° C. in the presence of a catalystsuch as trifluoroacetic acid, platinum catalysts (e.g. chloroplatinicacid), and the like, and in the presence of a solvent (e.g. liquidhydrocarbons, such as toluene and the like) for the polyoxyalkylenepolyether and polysiloxane reactants. The usual conventional amounts ofcomponents and reaction conditions can be employed and such is wellwithin the knowledge of one skilled in the art. For instance,approximately stoichiometric amounts or slightly higher of thepolyoxyalkylene polyether and the functional containing polysiloxanereactants (one hydroxy or alkenyloxy polyether group per silanichydrogen or silicon-bonded alkoxy, amino or halogen radical) arepreferred, while the amount of catalyst need obviously only be acatalytic amount. The temperature of the reaction, of course, largelydepends merely on the reactants involved and thepolysiloxane-polyoxyalkylene block copolymer desired to be produced.

The polysiloxane functional containing reactants used to produce thenovel polysiloxane-polyoxyalkylene block copolymers of this invention aswell as methods for their production are well known in the art.Illustrative of such polysiloxanes are those polymers consistingessentially of siloxy units of the formula R₂ SiO, siloxy units selectedfrom the group consisting of (R)(L)SiO and RSiO3/2 and terminal siloxyunits selected from the class consisting of those of the formulas R₃SiO1/2 and (R₂)(L)SiO1/2, wherein the average number of total siloxyunits per molecule of the polysiloxane polymer ranges from about 20 toabout 200, wherein from about 6 to about 15 percent of said total siloxyunits are selected from the group consisting of (R)(L)SiO and(R₂)(L)SiO1/2 and wherein there are no more than about four RSiO3/2siloxy units per average polysiloxane molecule, wherein R is the same asdefined above and wherein each L individually represents a functionalradical selected from the group consisting of hydrogen, alkoxy (e.g.methoxy, ethoxy and the like), halogen (e.g. chlorine and the like) andan amino radical e.g.-- N(CH.sub. 3)₂, and the like). Preferablypolysiloxanes wherein L is hydrogen or alkoxy are employed. Of course,the polyoxyalkylene polyether reactants employed are the novelpolyoxyalkylene polyether admixture compositions of matter of thisinvention defined above.

In addition, as mentioned above, the novel polysiloxane-polyoxyalkyleneblock copolymers of this invention can be produced in the same manner asjust described above, but in the absence of a solvent for thepolyoxyalkylene polyether and polysiloxane reactants and such asolventless process is the more preferred method for producing saidpolysiloxane-polyoxyalkylene block copolymers in view of thedisadvantages attendent to the use of a solvent as discussed above.

Accordingly, this invention includes an improved process for producingnovel polysiloxane-polyoxyalkylene block copolymers as defined abovewhich are suitable foam stabilizers for flexible polyether polyurethanefoam by reacting a functional containing polysiloxane polymer with apolyoxyalkylene polyether in the presence of a catalyst, the improvementwhich comprises carrying out the process in the absence of a solvent andemploying as the polyoxyalkylene polyether reactant the novelpolyoxyalkylene polyether admixture compositions of matter of thisinvention. The particular desired product, reactants and reactionconditions as well as their preferred embodiments have already beendefined above and are, of course applicable to the novel solventlessprocess of this invention.

As defined herein the average molecular weights of the variouspolyoxyalkylene polyether compounds in the novel polyether admixtures ofthis invention are calculated by dividing the molecular weight of thefunctional group (e.g. the hydroxy or allyloxy group) on the polyethercompound which is to be reacted with the functional containingpolysiloxane polymer starting material in the making of the novelpolysiloxane-polyoxyalkylene copolymers of this invention by the weightfraction of said functional group on said polyether compound.

The novel polysiloxane-polyoxyalkylene block copolymers of thisinvention as defined above contain several essential features. Forinstance, said block copolymers consist essentially of polysiloxane andpolyoxyalkylene blocks wherein these blocks are linked through a siliconto oxygen bond (e.g. where M is --O--) or a silicon to carbon bond (e.g.where M is --C_(n) H_(2n) O-- and n has a value of 2 or 3). Of course,it is to be understood that the novel polysiloxane-polyoxyalkylene blockcopolymers of this invention include copolymers simultaneouslycontaining both such types of bridging groups. That is to say that thesame block copolymer if desired can at the same time contain bothpolyoxyalkylene blocks linked through a silicon to oxygen bond andpolyoxyalkylene blocks linked through a silicon to carbon bond. Aspointed out the average polysiloxane copolymer of this inventionconsists essentially of from about 15 to about 35 percent by weight ofpolysiloxane blocks, the remainder of the copolymer (about 85 to about65 percent by weight) being constituted essentially of thepolyoxyalkylene blocks which are illustrated as an admixture of theformula --MX as defined above. Preferably the block copolymers of thisinvention consist essentially of from about 18 to about 27 percent byweight of polysiloxane blocks and from about 73 to about 82 percent byweight of polyoxyalkylene blocks. Further said block copolymers consistessentially of at least three different types of siloxy units, i.e.siloxy units of the formula R₂ SiO, siloxy units selected from the classconsisting of those of the formulas (R)(Q)SiO and RSiO3/2, and terminalsiloxy units selected from the class consisting of those of the formulasR₃ SiO_(1/2) and (R)₂ (Q) SiO_(1/2), wherein R and Q are the same asdefined above, with the proviso that said block copolymers contain nomore than about four (preferably about 1.2 to about 1.6) RSiO_(3/2)siloxy units per average polysiloxane molecule so as to avoid gellationof the copolymer. The average number of the total siloxy units permolecule of the polysiloxane-oxyalkylene block copolymer can range fromabout 20 to about 200; and from about 6 to about 15 percent said totalsiloxy units are selected from the group consisting of (R)(Q)SiO and(R₂)(Q)SiO, where R and Q are the same as defined above.

Typical of the monovalent hydrocarbon radicals free of aliphatic carbonto carbon multiple bonds represented by R in the formulas above arealkyl radicals (e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl,sec-butyl, isobutyl, t-butyl, n-octyl, decyl, dodecyl, and the like),cycloalkyl radicals (e.g. cyclohexyl, cycloheptyl, and the like), arylradicals (e.g. phenyl, naphthyl, and the like), aralkyl radicals (e.g.benzyl, 2-phenylethyl, and the like), and alkaryl groups (e.g. tolyl,and the like). Moreover R can also represent a substituted monovalenthydrocarbon radical so long as the substituent does not adversely effectthe desired result of the instant invention. Illustrative of suchsubstituted hydrocarbon radicals include halo-substituted alkyl and arylradicals, such as bromo-, chloro- and fluoro- substituted methyl, ethyl,propyl, and phenyl radicals, and the like. Preferably R represents alower alkyl radical having from 1 to 4 carbon atoms especially methyl.Thus the most preferred siloxy units are those of the formulas Me₂ SiO,(Me)(Q)SiO, MeSiO_(3/2), Me₃ SiO1/2 and (Me₂)(Q)SiO1/2 wherein Me is amethyl radical and Q is the same as defined above.

The symbol Q in the above siloxy unit formulas of the novelpolysiloxane-polyoxyalkylene block copolymers of this inventionrepresents a polyoxyalkylene polyether block having the formula --MXwherein M is the same as defined above and wherein X is apolyoxyalkylene radical consisting essentially of an admixture of UnitsA and B of the formula --(C₂ H₄ O)_(x) (C₃ H₆ O)_(y) Z wherein Z, x, y,Unit A and Unit B are the same as defined above. Accordingly, it isobvious that the formula --MX represents the polyoxyalkylene polyetherradical and block obtained upon the use of the above defined novelpolyoxyalkylene polyether admixtures of this invention in the productionof the novel polysiloxane-polyoxyalkylene block copolymers of thisinvention and that any particular desired --MX formula will merelydepend upon and correspond to the particular novel polyoxyalkylenepolyether admixture of this invention employed to produce the particularnovel polysiloxane-polyoxyalkylene block copolymer of this inventionthat is desired. Thus, the above definition and preferred embodiments ofthe novel polyoxyalkylene polyether admixtures of this invention equallycorrespond to the definition and preferred embodiments of the aboveformula --MX represented by the symbol Q in the siloxy unit formulas ofthe novel polysiloxane-polyoxyalkylene block copolymers of thisinvention. Of course, it is to be understood that the above formula (C₂H₄ O)_(x) (C₃ H₆ O)_(y) Z like the above formula Z'O(C₂ H₄ O)_(x) (C₃ H₆O)_(y) Z and the specific illustrations thereof as well as theexpression poly(oxyethylene-oxypropylene) copolymers as employed hereinare used to represent copolymers in which oxyalkylene groups are presentin random distribution (and indeed such is preferred) as well ascopolymers in which the oxyalkylene groups are present as blocks.Therefore, in no way should said formulas or the expressionpoly(oxyethylene-oxypropylene) copolymer be interpreted as merelyencompassing copolymers in which oxyalkylene groups are present inblocks, i.e., a block of oxyethylene and a block of oxypropylene. Ofcourse, it is to be also understood that the term propylene oxide andformula (C₃ H₆ O)_(y) employed herein refer to 1,2-propylene oxide andthe oxypropylene radical derived therefrom.

Accordingly, one preferred class of novel polysiloxane-polyoxyalkyleneblock copolymers of this invention is directed to polymers consistingessentially of R₂ SiO, (R)(Q)SiO and R₃ SiO1/2 siloxy units wherein Rand Q are the same as defined above.

A more preferred subclass of such polysiloxane-polyoxyalkylene blockcopolymers consists essentially of from about 19 to about 26 (morepreferably from about 20 to about 24) percent by weight of polysiloxaneblocks and from about 81 to about 74 (more preferably from about 80 toabout 76) percent by weight of polyoxyalkylene blocks, and furtherconsists essentially of from about 65 to about 140 (more preferably fromabout 100 to about 135) siloxy units of the formula (CH₃)₂ SiO, fromabout 6 to about 17 (more preferably from about 10 to about 15) siloxyunits of the formula CH₃ (Q)SiO, and two siloxy units of the formula(CH₃)₃ SiO1/2, wherein about 7 to about 14 (more preferably about 8 toabout 12) percent of the total siloxy units are CH₃ (Q)SiO units, andwherein each Q individually represents a polyoxyalkylene polyether blockhaving the formula --MX wherein M is a --C₃ H₆ O-- bridging group and Xis a polyoxyalkylene radical consisting essentially of an admixture ofUnits A and B of the formula (C₂ H₄ O)_(x) (C₃ H₆ O)_(y) Z wherein Z isa terminal group selected from the class consisting of alkyl, aryl,aralkyl and acyl (more preferably methyl or n-butyl) radicals, thevalues of x and y being determined by the following conditionsprevailing for Units A and B;

Unit A representing from about 25 to about 50 preferably from about 35to about 45) percent by weight of low molecular weight polyoxyalkylenepolyether copolymer based on the total weight of Units A and B in saidadmixture, said polyether copolymer having an average molecular weightin the range of from about 900 to about 1300 and wherein from about 20to about 60 (more preferably about 30 to about 55) weight percent of theoxyalkylene groups of said polyether copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene; and

Unit B representing from about 75 to about 50 (more preferably fromabout 65 to about 55) percent by weight of high molecular weightpolyoxyalkylene polyether copolymer based on the total weight of Units Aand B in said admixture, said polyether copolymer having an averagemolecular weight in the range of from about 3800 to about 5000 (morepreferably from about 4000 to about 5000), and wherein from about 20 toabout 60 (more preferably from about 30 to about 55) weight percent ofthe oxyalkylene groups of said polyether copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene; with the addedproviso that said admixture of Units A and B has an average molecularweight in the range of from about 1800 to about 2600 (more preferablyfrom about 2000 to about 2400).

Another more preferred subclass of such polysiloxane-polyoxyalkyleneblock copolymers consists essentially of from about 19 to about 26(morepreferably from about 20 to about 24) percent by weight of polysiloxaneblocks and from about 81 to about 74 (more preferably from about 80 toabout 76) percent by weight of polyoxyalkylene blocks, and furtherconsists essentially of from about 25 to about 65 (more preferably fromabout 40 to about 60) siloxy units of the formula (CH₃)₂ SiO from about3.5 to about 7.5 (more preferably from about 4 to about 7) siloxy unitsof the formula CH₃ (Q)SiO and two siloxy units of the formula (CH₃)₃SiO1/2, wherein about 10 to about 12 percent of the total siloxy unitsare CH₃ (Q)SiO units, and wherein each Q individually represents apolyoxyalkylene polyether block having the formula --MX wherein M is a--C₃ H₆ O-- bridging group and X is a polyoxyalkylene radical consistingessentially of an admixture of Units A and B of the formula (C₂ H₄O)_(x) (C₃ H₆ O)_(y) Z wherein Z is a terminal group selected from theclass consisting of alkyl, aryl, aralkyl and acyl (more preferablymethyl or n-butyl) radicals, the values of x and y being determined bythe following conditions prevailing for Units A and B;

Unit A representing from about 35 to about 45 percent by weight of lowmolecular weight polyoxyalkylene polyether copolymer based on the totalweight of Units A and B in said admixture, said polyether copolymerhaving an average molecular weight in the range of from about 800 toabout 1300, and wherein from about 20 to about 60 (more preferably about30 to about 55) weight percent of the oxyalkylene groups of saidpolyether copolymer are oxyethylene, the remainder of the oxyalkylenegroups being oxypropylene; and

Unit B representing from about 65 to about 55 percent by weight of ablend of two high molecular weight polyoxyalkylene polyether copolymersbased on the total weight of Units A and B in said admixture said blendconsisting of from about 50 to about 75 (more preferably from about 60to about 70) percent by weight of a polyoxyalkylene polyether copolymerhaving an average molecular weight in the range of from about 3000 toabout 3400, wherein from about 20 to about 60(more preferably from about30 to about 55) weight percent of the oxyalkylene groups of saidpolyether copolymer are oxyethylene, the remainder of the oxyalkylenegroups being oxypropylene, and from about 50 to about 25 (morepreferably from about 40 to about 30) percent by weight of apolyoxyalkylene polyether copolymer having an average molecular weightin the range of from about 3800 to about 5000, wherein from about 20 toabout 60 (more preferably from about 30 to about 55) weight percent ofthe oxyalkylene groups of said polyether copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene; with the provisothat said polyether copolymer blend has an average molecular weight inthe range of from about 3400 to about 4000 (more preferably from about3400 to about 3800); and with the added proviso that said admixture ofUnits A and B has an average molecular weight in the range of about 1600to about 2100 (more preferably from about 1700 to about 1900).

Another class of novel polysiloxane-polyoxyalkylene block copolymers ofthis invention is directed to polymers consisting essentially of R₂ SiO,(R)(Q)SiO and (R₂)(Q)SiO1/2 siloxy units wherein R and Q are the same asdefined above.

Still another class of novel polysiloxane-polyoxyalkylene blockcopolymers of this invention is directed to polymers consistingessentially of R₂ SiO, (R)(Q)SiO, RSiO3/2, and R₃ SiO1/2 siloxy units,wherein R and Q are the same as defined above. Yet another class ofnovel polysiloxane-polyoxyalkylene block copolymers of this invention isdirected to polymers consisting essentially of R₂ SiO,(R)(Q)SiO,RSiO3/2, and (R₂)(Q)SiO siloxy units wherein R and Q are thesame as defined above.

Finally another preferred class of polysiloxane-polyoxyalkylene blockcopolymers of this invention is directed to polymers consisting of R₂SiO, RSiO3/2, and (R₂)(Q)SiO siloxy units, wherein R and Q are the sameas defined above.

A more preferred subclass of such polysiloxane-polyoxylakylene blockcopolymers consists essentially of from about 17 to about 26 (morepreferably from about 19 to about 24) percent by weight of polysiloxaneblocks and from about 83 to about 74 (more preferably from about 81 toabout 76) percent by weight of polyoxyalkylene blocks, and furtherconsists essentially of from about 17 to about 24 siloxy units of theformula (CH₃)₂ SiO, from about 1.2 to about 1.8 siloxy units of theformula CH₃ SiO₁.5 and from about 3 to about 4 siloxy units of theformula (CH₃)₂ QSiO1/2, and wherein each Q individually represents apolyoxyalkylene polyether block having the formula --MX wherein M is a--O-- bridging group and X is a polyoxyalkylene radical consistingessentially of an admixture of Units A and B of the formula (C₂ H₄O)_(x) (C₃ H₆ O)_(y) Z wherein Z is a terminal group selected from theclass consisting of alkyl, aryl and aralkyl (more preferably n-butyl)radicals, the values of x and y being determined by the followingconditions prevailing for Units A and B;

Unit A representing from about 30 to about 40 percent by weight of lowmolecular weight polyoxyalkylene polyether copolymer based on the totalweight of Units A and B in said admixture, said polyether copolymerhaving an average molecular weight in the range of from about 900 toabout 1300, wherein from about 20 to about 60 (more preferably fromabout 30 to about 55) weight percent of the oxyalkylene groups of saidpolyether copolymer are oxyethylene, the remainder of the oxyalkylenegroups being oxypropylene; and

Unit B representing from about 70 to about 60 percent by weight of ablend of two high molecular weight polyoxyalkylene polyether copolymersbased on the total weight of Units A and B in said admixture, said blendconsisting of from about 55 to about 70 percent by weight of apolyoxyalkylene polyether copolymer having an average molecular weightin the range of from about 3000 to about 3400, wherein from about 20 toabout 60 (more preferably from about 30 to about 55) weight percent ofthe oxyalkylene groups of said polyether copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, and from about45 to about 30 percent by weight of a polyoxyalkylene polyethercopolymer having an average molecular weight in the range of from about3800 to about 5500 (more preferably from about 4000 to about 5000),wherein from about 20 to about 60 (more preferably from about 30 toabout 55) weight percent of the oxyalkylene groups of said polyethercopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene; with the proviso that said polyether copolymer blend hasan average molecular weight in the range of from about 3400 to about4000 (more preferably from about 3400 to about 3800); and with the addedproviso that said admixture of Units A and B has an average molecularweight in the range of from about 1600 to about 2100 (more preferablyfrom about 1700 to about 1900).

Of course, it is to be understood that the polysiloxane-polyoxyalkyleneblock copolymers of this invention can contain small amounts of othersiloxy units e.g. SiH groups (owing to incomplete reaction thereof withthe polyoxyalkylene reactant) and/or Si-alkoxy or Si-OH groups owing tothe incomplete hydrolysis and condensation of the silanes used toproduce the siloxane reactant.

The novel polysiloxane-polyoxyalkylene block copolymers of thisinvention are normally liquid homogeneous compositions and comprisemixtures of polymer species which differ in molecular weight, polyetherand siloxane contents and relative number of monomeric units. It is tobe understood, therefore, that as expressed herein the values of theseparameters are average values. It is to be also understood that a smallamount of the polyoxyalkylene blocks may comprise residual uncappedhydroxyl-terminated groups introduced with the polyoxyalkylene etherreactants.

The above described novel polysiloxane-polyoxyalkylene block copolymersof this invention are unique in that they have been found to beexcellent efficient foam stabilizers for flexible polyether polyurethanefoam regardless of whether prepared in the presence or absence ofsolvent. Moreover, they have been found to be extremely potentstabilizers in relation to other polysiloxane-polyoxyalkylene blockcopolymers falling outside of the scope of this invention. For example,it has been found that a smaller amount of thepolysiloxane-polyoxyalkylene block copolymers of this invention need beemployed to achieve a given level of performance as foam stabilizers forflexible polyether polyurethane foam than is required by certain otherpolysiloxane-polyoxyalkylene block copolymers falling outside of thescope of this invention. The polysiloxane-polyoxyalkylene blockcopolymers have also been found to provide greater latitude in theamount of tin catalyst required in the manufacture of flexible polyetherpolyurethane foam thereby giving one greater control over the productionand quality (height of rise, cells per inch and air flow rate) of thefoam desired. Thus, excellent open (porous) foams can be achieved evenover a broad range of operating conditions, such as tin catalystconcentrations, by this invention.

Thus the novel polysiloxane-polymers of this invention can be employedas foam stabilizers in the production of flexible polyether polyurethanefoam as a 100 percent active stream or in dilute foam as a solution invarious types of organic liquids including polar and nonpolar solvents.For example, the polymers may be diluted with nonpolar solvents such asthe normally liquid aliphatic and aromatic unsubstituted andhalogen-substituted hydrocarbons such as heptane, xylene, toluene,chlorobenzene and the like. When used, the preferred diluents arecompounds encompassed by the formula:

    Z"'O(Z"O).sub.t Z""

wherein:

Z"' is hydrogen or a monovalent hydrocarbon group including alkyl (e.g.methyl, ethyl, propyl and butyl), aryl (e.g., phenyl and tolyl) andaralkyl (e.g., benzyl) groups; Z" is a bivalent alkylene group (e.g.,ethylene, propylene, trimethylene and butylene);

Z"" is a monovalent hydrocarbon group such as defined for Z"', and

t has an average value of at least two.

When Z"' is hydrogen, it is preferred that such Z"'O groups (that is,--OH) represent no more than about 5 weight percent of the solvent.Illustrative solvents are alkylene oxide adducts of starters such aswater, mono-ols, diols and other polyols, while such organic startersare typically illustrated by butanol, propylene glycol, glycerol and1,2,6-hexantriol. Preferred adducts of the organic starters are themixed alkylene oxide adducts, particularly those containing acombination of oxyethylene and oxypropylene units. For example, oneclass of such preferred organic solvents are mixed ethyleneoxide-propylene oxide adducts of butanol which are represented by thegeneral formula, HO(C₂ H₄ O)_(s) (C₃ H₆ O)_(u) C₄ H₉, wherein s has anaverage value from about 8 to about 50, and u has an average value fromabout 6 to about 40. Preferably, the values of s and u are such that theweight percent of oxyethylene units is about equal to the weight percentof the oxypropylene units. When employed, the solution compositionspreferably contain from about 25 to about 80 parts by weight of thepolysiloxane-polyoxyalkylene block copolymers per 100 parts by weight ofthe total weight of block copolymer and solvent, but can contain from 1to 99 parts by weight of the block copolymer.

The novel polysiloxane-polyoxyalkylene block copolymers of thisinvention may also be used in combination with non ionic organicsurfactants such as adducts produced by reacting k mols of ethyleneoxide (wherein k has an average value from about 4 to about 40,inclusive of whole and fractional numbers) per mol of any of thefollowing hydrophobes: n-undecyl alcohol, myristyl alcohol, laurylalcohol, trimethyl nonanol, tridecyl alcohol, pentadecyl alcohol, cetylalcohol, nonylphenol, dodecylphenol, tetradecylphenol and the like.Especially useful are ethylene oxide adducts of the nonylphenol havingthe average composition, C₉ H₁₉ -C₆ H₄ -(OC₂ H₄)_(n) OH, wherein n hasan average value from about 9 up to about 20 or more, including wholeand fractional numbers such as 9, 10.5, 13, 14.5, and 15. When used,such nonionic organic surfactants are used in amounts from about 2 toabout 20 parts by weight per 100 parts by weight of the block copolymer.It is to be understood that such additives may also be present as acomponent of the aforementioned solutions of the block copolymers.

Also included within the scope of this invention is the use of the novelpolysiloxane-polyoxyalkylene block copolymers of this invention incombination with other types of silicon-containing surfactants such as,for example, those described in U.S. Pat. Nos. 2,834,748; 3,505,377 and3,657,305. When used, the additional organosilicone surfactant is usedin a minor amount which is usually from about 1 to about 30 parts byweight per 100 parts by weight of the novel polysiloxane-polyoxyalkyleneblock copolymer of this invention.

In addition to the novel polysiloxane polyoxyalkylene block copolymersof the present invention, the other essential types of components andreactants employed in providing flexible polyether polyurethane foams asdescribed herein are polyether polyols, organic polyisocyanates, thecatalyst system and blowing agent.

In producing the flexible polyether polyurethane foams of the presentinvention, one or more polyether polyols is employed for reaction withthe polyisocyanate reactant to provide the urethane linkage. Suchpolyols have an average of at least two, and usually not more than six,hydroxyl groups per molecule and include compounds which consist ofcarbon, hydrogen and oxygen and compounds which also contain phosphorus,halogen and/or nitrogen.

Such polyether polyols are well known in the art and include, forexample, polyethers exemplified by the following classes of composition:

(a) Polyoxyalkylene polyols including alkylene oxide adducts of, forexample, water; ethylene glycol; diethylene glycol; propylene glycol;1,5-pentanediol; hexylene glycol; dipropylene glycol; trimethyleneglycol; 1,2-cyclohexanediol; 3-cyclohexane-1, 1-dimethanol anddibromo-derivatives thereof; glycerol; 1,2,6-hexanetriol;1,1,1-trimethylolethane; 1,1,1-trimethylolpropane; 3-(2-hydroxyethoxy)-and 3-(2-hydroxypropoxy)-1,2-propanediols;2,4-dimethyl-2-(2-hydroxyethoxy)methylpentanediol-1,5;1,1,1-tris[(2-hydroxyethoxy)methyl]ethane;1,1,1-tris[(2-hydroxypropoxy)methyl]propane; pentaerythritol; sorbitol;susrose; lactose; alpha-methyl glucoside; alpha-hydroxyalkylglucoside;ammonia; triethanolamine; triisopropanolamine; ethylenediamine,diethylenetriamine, novolac resins; phosphoric acid; benzenephosphoricacid; polyphosphoric acids such as tripolyphosphoric acid andtetrapolyphosphoric acid; phenolaniline; formaldehyde tertiarycondensation products; aniline-formaldehyde condensation products; andthe like. The alkylene oxides employed in producing the polyoxyalkylenepolyols normally have 2 to 4 carbon atoms. Propylene oxide and mixturesof propylene oxide with ethylene oxide are preferred.

(b) Polymer/polyether polyols which are produced by polymerizing one ormore ethylenically unsaturated monomers dissolved or dispersed in apolyether polyol is in the presence of a free radical catalyst. Suitablepolyether polyols for producing such compositions include, for example,any of the above described polyols encompassed by paragraph (a) above.Illustrative of suitable ethylenically unsaturated monomers are thoseencompassed by the general formula ##STR1## where: R' is hydrogen,methyl or any of the halogens (i.e., fluorine, chlorine, bromine oriodine); and R" is R', cyano, phenyl, methyl-substituted phenyl, oralkenyl radicals having from 2 to 6 carbon atoms such as vinyl, allyland isopropenyl groups. Typical examples of such polymerizable monomersare the following which may be employed individually or in combination:ethylene, propylene, acrylonitrile, methacrylonitrile, vinyl chloride,vinylidene chloride, styrene, alphamethylstyrene, and butadiene. Theseand other polymer/polyol compositions which are suitably employed eitherindividually or in combination with polyethers mentioned in paragraph(a) above are described in British Pat. No. 1,063,222 and U.S. Pat. No.3,383,351, the disclosures of which are incorporated herein byreference. Such compositions are prepared by polymerizing the monomersin the polyol at a temperature between about 40° C. and about 150° C.employing any free radical-generating initiator including peroxides,persulfates, percarbonates, perborates, and azo compounds, such as, forexample, hydrogen peroxide, dibenzoyl peroxide, benzoyl hydroperoxide,lauroyl peroxide, and azobis(isobutyronitrile). The polymer/polyetherpolyol product may also contain a small amount of unreacted polyether,monomer and free polymer.

(c) Lactone polyols prepared by reacting a lactone such asepsilon-caprolactone or a mixture of epsilon-caprolactone and analkylene oxide with a polyfunctional initiator such as a polyhydricalcohol, an amine, or an aminoalcohol, are also useful.

(d) Phosphorus-containing derivatives such as tris(dipropylene)glycolphosphite and other phosphites are also useful.

In preparing the flexible polyether polyurethane foams in accordancewith the present invention it is, of course, to be understood that anyof the aforesaid polyether polyols or mixtures thereof can be employedas reactants with the organic polyisocyanate. The particular polyetherpolyol or polyols employed merely depends upon the desired end-use ofthe polyurethane foam. Usually diols provide soft foams, firmer foamsare obtained by the incorporation of polyether polyols having more thantwo hydroxyl groups, including triols, tetra-ols, pentols and hexols.When it is desired to produce polyurethanes having comparatively highload-bearing properties and/or diecutability, polymer/polyether polyolsof the aforesaid type are used.

The hydroxyl number of the polyether polyol reactant including mixturesof polyols employed in the production of the flexible polyurethane foamsof this invention may vary over a relatively wide range such as fromabout 20 to about 150, and is usually no higher than about 80. As iswell known in this art, the hydroxyl numbers are determined by, and aredefined as, the number of milligrams of potassium hydroxide required forthe complete neutralization of the hydrolysis product of the fullyacetylated derivative prepared from 1 gram of polyol or mixture ofpolyols. The hydroxyl number is also defined by the following equationwhich indicates its relationship with the molecular weight andfunctionality of the polyol: ##EQU1## wherein OH= hydroxyl number of thepolyol,

f= average functionality, that is, the average number of hydroxyl groupsper molecule of polyol and

M.W.= average molecular weight of the polyol.

The organic polyisocyanates that are useful in producing flexiblepolyether polyurethane foam in accordance with the process of thisinvention are well known in the art and are organic compounds thatcontain at least two isocyanato groups and any such compounds ormixtures thereof may be employed. Among such suitable polyisocyanatesare those conveniently represented by the general formula:

    D(NCO).sub.i

wherein i is an integer of two or more and D is an organic radicalhaving the valence of i. D can be a substituted or unsubstitutedhydrocarbon group (e.g., alkylene, cycloalkylene, arylene, alkarylene,aralkylene and the like). D can also be a group having the formulaD'-T-D' wherein D' is an alkylene or arylene group and T is a divalentmoiety such as --O--, --O--D'--O--, --C(O)--, --S--, --S--D'--S--, or--SO₂ --.

Illustrative of suitable organic polyisocyanate reactants are thefollowing including mixtures thereof: 1,2-diisocyanato-ethane;1,3-diisocyanato-propane; 1,2-diisocyanato-propane;1,4-diisocyanato-butane; 1,5-diisocyanato-pentane;1,6-diisocyanato-hexane; 1,5-diisocyanato-2, 2-dimethyl-pentane;1,7-diisocyanato-heptane; 1,5-diisocyanato-2, 2,4-trimethyl-pentane;1,8-diisocyanato-octane; 1,9-diisocyanato-nonane;1,10-diisocyanato-decane; 1, 11-diisocyanato-undecane;1,12-diisocyanato-dodecane; 1,6-diisocyanato-3-methoxy-hexane;1,6-diisocyanato-3-butoxy-hexane; bis(3-isocyanato-propyl)ether; thebis(3-isocyanato-propyl)ether of 1,4-butylene glycol; (OCNCH₂ C H₂ CH₂CH₂ OCH)₂ O; bis(2-isocyanatoethyl) carbonate; 1-methyl-2,4-diisocyanato-cyclohexane; 1,8-diisocyanato-p-methane; bis5,6-(2-isocyanatoethyl)bicyclo[2.2.1]-hept-2-ene;bis(3-isocyanato-propyl)sulfide; bis(isocyanato-hexyl)sulfide;1,4-phenylene-diisocyanate; 2,4-tolylene-diisocyanate;2,6-tolylene-diisocyanate; crude tolylene diisocyanates; xylylenediisocyanates; 4-chloro-1,3-phenylene-diisocyanate; 4-bromo-1,3-phenylene-diisocyanate; 4-nitro-(1,3 or 1,5)-phenylene-diisocyanate;4-ethoxy-1,3-phenylene- arisocyanate; benzidine diisocyanate; toluidinediisocyanate; dianisidine diisocyanate; 2,4'-or4,4'-diisocyanatodibenzyl; ether; diphenylmethane-4,4'-diisocyanate;4,4'-diisocyanatodibenzyl; isopropyl-benzene-alpha-4-diisocyanate;1,5-diisocyanato-naphthalene; 1,8-diisocyanato-naphthalene;9,10-diisocyanato-anthracene; triphenyl-methane-4,4', 4"-triisocyanate;2,4,6-toluene triisocyanate; and many other organic polyisocyanates thatare known in the art such as those disclosed in an article by Siefken,Ann., 565,75 (1949). In general, the aromatically unsaturatedpolyisocyantes are preferred.

Further included among the isocyanates useful in the process of thisinvention are dimers and trimers of isocyanates and diisocyanates andpolymeric diisocyanates such as those having the general formula:

    [D(NCO).sub.i ].sub.j

in which i and j are integers of two or more, and/or (as additionalcomponents in the reaction mixtures) compounds of the general formula:

    L'(NCO).sub.i

in which i is one or more and L' is a monofunctional or polyfunctionalatom or radical. Examples of this type include ethylphosphonicdiisocyanate, C₂ H₅ P(O)(NCO)₂ ; phenylphosphonic diisocyanate, C₆ H₅P(O)(NCO)₂ ; compounds containing an .tbd.Si--NCO group, isocyanatesderived from sulfonamides (DSO₂ NCO), cyanic acid, thiocyanic acid, andcompounds containing a metal-NCO radical such as tributyltin isocyanate.

Also, included as useful in the preparation of the flexible polyetherpolyurethane foams in accordance with the process of this invention arethe polyisocyanates of the aniline-formaldehyde polyaromatic type whichare produced by phosgenation of the polyamine obtained by acid-catalyzedcondensation of aniline with formaldehyde. Poly(phenylmethylene)polyisocyanates of this type are available commercially under such tradenames as PAPI, NIAX Isocyanate AFPI, Mondur MR, Isonate 390 P, ThanateP-220, NCO-120 and NCO-20. These products are low viscosity (50-500centipoises at 25° C.) liquids having average isocyanato functionalitiesin the range of about 2.25 to about 3.2 or higher, depending upon thespecific aniline-to-formaldehyde molar ratio used in the polyaminepreparation.

Other useful polyisocyanates are combinations of diisocyanates withpolymeric isocyanates containing more than two isocyanato groups permolecule. Illustrative of such combinations are: a mixture of2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate and the aforesaidpoly(phenylmethylene) polyisocyanates; and a mixture of isomerictolylene diisocyanates with polymeric tolylene diisocyanates obtained asresidues from the manufacture of the diisocyanates.

On a combined basis, the polyether polyol and organic polyisocyanatereactants usually constitute the major proportion by weight of thepolyurethane-forming reaction mixture. In general, the polyisocyanateand polyether polyol reactants are employed in relative amounts suchthat the ratio of total-- NCO equivalents to total active hydrogenequivalent (of the polyether polyol and any water, when used) is from0.8 to 1.5, preferably from 0.9 to 1.1, equivalents of-- NCO perequivalent of active hydrogen. This ratio is known as the IsocyanateIndex and is often also expressed as a percent of the stoichiometricamount of polyisocyanate required to react with total active hydrogen.When expressed as a percent, the Isocyanate Index may be from 80 to 150,and is preferably within the range from about 90 to 110.

The urethane-forming reaction is effected in the presence of a minoramount of catalyst, preferably an amine catalyst and usually a tertiaryamine. Suitable amine catalysts include one or more of the following:N-methylmorpholine; N-ethylmorpholine; N-octadecylmorpholine;triethylamine; tributylamine; trioctylamine;N,N,N',N'-tetramethyl-ethylenediamine;N,N,N',N'-tetramethyl-1,3-butane-diamine; triethanolamine;N,N-dimethylethanolamine; triisopropanolamine; N-methyldiethanolamine;hexadecyldimethylamine; N,N-dimethylbenzylamine; trimethylamine;N,N-dimethyl-2-(2-dimethylaminoethoxy)ethylamine, also known asbis(2-dimethylaminoethyl)ether; triethylenediamine (i.e.,1,4-diazabicyclo[2.2.2.]octane); the formate and other salts oftriethylenediamine, oxyalkylene adducts of the amino groups of primaryand secondary amines and other such amine catalysts which are well knownin the art of polyurethane manufacture such as the beta-amino carbonylcatalysts of U.S. Pat. No. 3,821,131 especially3-dimethylamino-N,N-dimethylpropionamide. The amine catalyst may beintroduced to the polyurethane-producing reaction mixture as such or asa solution in suitable carrier solvents such as diethylene glycol,dipropylene glycol, and 2-methyl-2,4-pentanediol ("hexylene glycol")preferably the amine catalyst is generally present in the finalurethane-producing reaction mixture in an amount of from about 0.05 toabout 3 parts by weight of active catalyst (that is, the amine exclusiveof other components present in solutions thereof) per 100 parts byweight of the polyether polyol reactant.

It is also preferred to include a minor amount of certain metalcatalysts in addition to the amine catalyst in the component of thereaction mixture a minor amount of production of the polyurethane foam.Such supplementary catalysts are well known to the art of flexiblepolyether-based polyurethane foam manufacture. For example, useful metalcatalysts include organic derivatives of tin, particularly tin compoundsof carboxylic acids such as stannous octoate, stannous oleate, stannousacetate, stannous laurate, dibutyl tin dilaurate, and other such tinsalts. Additional metal catalysts are organic derivatives of otherpolyvalent metals such as zinc and nickel (e.g., nickelacetylacetonate). In general, the amount of such metal cocatalysts whichcan be present in the polyurethane-producing reaction mixture is withinthe range from about 0.05 to about 2 parts by weight per 100 parts byweight of the polyether polyol reactant.

Foaming is accomplished by employing a small amount of a polyurethaneblowing agent such as water in the reaction mixture (e.g. about 0.5 toabout 5 weight) percent of water, based on the total weight of thereaction mixture which upon reaction with isocyanate generates carbondioxide in situ, or through the use of blowing agents which arevaporized by the exotherm of the reaction, or by a combination of thetwo methods. These various methods are known in the art. Thus, inaddition to or in place of water, other blowing agents which can beemployed in the process of this invention include methylene chloride,liquefied gases which have boiling points below 80° F. and above -60°F., or other inert gases such as nitrogen, carbon dioxide added as such,methane, helium and argon. Suitable liquefied gases include aliphaticand cycloaliphatic fluorocarbons which vaporize at or below thetemperature of the foaming mass. Such gases are at least partiallyfluorinated and may also be otherwise halogenated. Fluorocarbon blowingagents suitable for use in foaming the formulations of this inventioninclude trichloromonofluormethane, dichlorodifluoromethane,1,1-dichloro-1 -fluoroethane,1,1,1-trifluoro-2-fluoro-3,3-difluoro-4,4,4-trifluorobutane,hexafluorocyclobutene, octafluorocyclobutane and the like. Anotheruseful class of blowing agents include thermally-unstable compoundswhich liberate gases upon heating, such asN,N'-dimethyl-N,N'-dinitrosoterephthalamide, and the like. The generallypreferred method of foaming for producing flexible foams is the use ofwater or a combination of water plus a fluorocarbon blowing agent suchas trichloromonofluoromethane. The amount of blowing agent employed inthe foaming reaction will vary with factors such as the density that isdesired in the foamed product. Usually, however, from about 1 to about30 parts by weight of the blowing agent per 100 parts by weight of thepolyether polyol reactant is preferred.

The polyether-based polyurethane foams of this invention may be formedin accordance with any of the processing techniques known to the artsuch as, in particular, the "one-shot" technique. In accordance withthis method, foamed products are provided by carrying out the reactionof the polyisocyanate and polyether polyol silultaneously with thefoaming operation. It is sometimes convenient to add thepolysiloxane-polyoxyalkylene block copolymer foam stabilizer to thereaction mixture as a premixture with one or more of the blowing agent,polyether polyol, and catalyst components.

It is to be understood that the relative amounts of the variouscomponents of the foam formulations are not narrowly critical. Thepolyether polyol and polyisocyanate are present in the foam-producingformulation in a major amount. The relative amounts of these twocomponents is the amount required to produce the desired urethanestructure of the foam and such relative amounts are well known in theart. The blowing agent, catalyst and polysiloxane-polyoxyalkylene blockcopolymer foam stabilizer are each present in a minor amount necessaryto achieve the function of the component. Thus, the blowing agent ispresent in an amount sufficient to foam the reaction mixture, thecatalyst is present in a catalytic amount (i.e., an amount sufficient tocatalyze the reaction to produce the urethane at a reasonable rate), andthe polysiloxane-polyoxyalkylene block copolymers of this invention arepresent in a foam-stabilizing amount, that is, in an amount sufficientto stabilize the foam. The preferred amounts of these various componentsare as given hereinabove.

If desired other additional ingredients can be employed in minor amountsin producing the polyurethane foams in accordance with the process ofthis invention. Illustrative of such additives that can be employed are:cross-linking agents such as glycerol, triethanolamine and theiroxyalkylene adducts, as well as fillers, dyes, pigments, anti-yellowingagents and the like. Flame-retardant agents can also be employed ifdesired. Such flame retardants are well known in the art and include avariety of compounds which preferably contain phosphorus or halogen orboth phosphorus and halogen. Illustrative of such flame retardant agentsinclude those disclosed in U.S. application Ser. No. 279,883 filed Aug.11, 1972, now U.S. Pat. No. 3,846,462 and Nos. 3,075,927; 3,075,928;3,222,305; and 3,574,149.

The polyurethanes produced in accordance with the present invention canbe used in the same areas as conventional flexible polyetherpolyurethanes. For example, the foams of the present invention can beused with advantage in the manufacture of textile interliners, cushions,mattresses, paddings, carpet underlay, packaging, gaskets, sealers,thermal insulators and the like.

The following examples are illustrative of the present invention and arenot to be regarded as limitative. In the following examples the terms,abbreviations and symbols used have the following indicated meanings.

DEFINITIONS

*: An asterisk (*) beside the number of an example appearing belowindicates that the example is presented for purpose of comparison anddoes not illustrate the present invention.

C.: Centigrade

conc.: Concentration

cstks. Centistokes at 25° C. or cs.:

g.: Grams

hr.: Hour

in.: Inch

lbs.: Pounds

Me: Methyl

ml.: Milliliter

mm.: Millimeters

Polyol I:

A polyol produced from glycerol and a mixture of 86 weight percentpropylene oxide and 14 weight percent ethylene oxide. Polyol I has ahydroxyl number of 46.

Polyol II:

A polyol produced from glycerol and a mixture of 84 weight percentpropylene oxide and 16 weight percent ethylene oxide. Polyol II has ahydroxyl number of 46.

Scfm:

standard cubic feet per minute.

Tdi:

a mixture of 80 weight-percent 2,4-tolylene diisocyanate and 20weight-percent 2,6-tolylene diiocyanate.

visc.:

Viscosity

POLYURETHANE FOAM PROPERTIES

The formulations and procedures for the polyurethane foam tests referredto in the examples are shown below.

    ______________________________________                                        Tests, I, II, III, IV, V and VI                                               ______________________________________                                        Formulation                                                                   Material            Parts by Weight                                           ______________________________________                                        Polyol I            100.0                                                     Distilled water     4.85                                                      Dimethylethanol amine                                                                             0.35                                                      CCl.sub.3 F         15.0                                                      Stannous octoate    0.3                                                       TDI                 56.9                                                      Polysiloxane-polyoxyalkylene                                                  block copolymer:    Varied                                                      Test I            0.90                                                        Test II           0.70                                                        Test III          0.60                                                        Test IV           0.50                                                        Test V            0.40                                                        Test VI           0.30                                                      ______________________________________                                    

The foams were produced by adding the polysiloxane-polyoxyalkylene blockcopolymer to Polyol I in a 1000 ml. container, mixing with a spatula,adding a mixture of the water and amine to the container, adding CCl₃ Fto the container, mixing with a drill press for 15 seconds adding thestannous octoate, mixing for 8 seconds with a drill press adding theTDI, mixing with a drill press for 7 seconds, pouring into a mold andcuring for 15 minutes at 135° C. Prior to the cure the temperature ofthe materials was maintained at no higher than 25° C. In view of thedifferences in the amounts of block copolymer used, Test VI is a morerigorous test than Test V; Test V is a more rigorous test than Test IV;Test IV is a more rigorous test than Test III; Test III is a morerigorous test than Test II; and Test II is a more rigorous test thanTest I for evaluating the copolymers as polyurethane foam stabilizers.

FOAM EVALUATION

The following terms are used in the examples in connection with theabove-described polyurethane foam tests:

Foam Rise

The Foam Rise is the height of the cured polyurethane foam in inches.

Efficiency

The efficiency of a polysiloxane-polyoxyalkylene block copolymercomposition denotes the effectiveness of the composition as apolyurethane foam stabilizer. At a given concentration, a more efficientcomposition will result in a higher Foam Rise value.

Cells Per Inch

This denotes the number of cells in the polyurethane foam per linearinch of the foam. The greater the cells per inch value, the finer thecell structure.

Air Flow

This is the rate of flow of air in standard cubic feet per minute at 0.5inch water positive pressure through a one inch thick block of foamhaving a cross-section of two inches by two inches. The Air Flow valueis related to the porosity of the foam. The higher the Air Flow value,the more porous the foam.

Failed

This denotes that the composition tested was not a polyurethane foamstabilizer in that either no foam was produced or a foam was producedbut collapsed.

EXAMPLE 1

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 162 g. of a polyether admixture having anaverage molecular weight of about 2,100 and consisting of about 78percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1900wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 22 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 200 g. oftoluene; (3) about 0.6 g. of trifluoroacetic acid catalyst, about 0.28g. of potassium acetate cocatalyst, and (4) about 40 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO, and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to aone-liter, agitated, glass reaction vessel fitted with a distillationcolumn and still head. The reaction mixture was heated to reflux.Ethanol was removed at the still head operated at a partial reflux as atoluene-ethanol azeotrope until the temperature at the still headremained about at least 105° C. Then toluene was essentially the onlyvolatile component in the reaction mixture. The reaction mixture wasthen neutralized with sodium bicarbonate and the toluene was removed bydistillation the residue was then filtered to remove residual sodiumbicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, having a viscosity of about 1000 cs., said blockcopolymer consisting essentially of about 19.5 percent by weight ofpolysiloxane blocks and about 80.5 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 2

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 162 g. of a polyether admixture having anaverage molecular weight of about 2,100 and consisting of about 78percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1900wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 22 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 140 g. oftoluene; (3) about 0.6 g. of trifluoroacetic acid catalyst, about 0.28g. of potassium acetate cocatalyst; and (4) about 40 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO, and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to aone-liter, agitated, glass reaction vessel fitted with a distillationcolumn and still head. The reaction mixture was heated to reflux.Ethanol was removed at the still head operated at a partial reflux as atoluene-ethanol azeotrope until the temperature at the still headremained about at least 105° C. Then toluene was essentially the onlyvolatile component in the reaction mixture. The reaction mixture wasthen neutralized with sodium bicarbonate and the toluene was removed bydistillation the residue was then filtered to remove residual sodiumbicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 1000 cs., said blockcopolymer consisting essentially of about 19.5 percent by weight ofpolysiloxane blocks and about 80.5 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 3

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 162 g. of a polyether admixture having anaverage molecular weight of about 2,100 and consisting of about 78percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1900wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene. Said oxyalkylene groups being present in the copolymer ina random distribution, and about 22 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 110 g. oftoluene; (3) about 0.6 g. of trifluoroacetic acid catalyst, about 0.28g. of potassium acetate cocatalyst; and (4) about 40 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO, and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to aone-liter, agitated, glass reaction vessel fitted with a distillationcolumn and still head. The reaction mixture was heated to reflux.Ethanol was removed at the still head operated at a partial reflux as atoluene-ethanol azeotrope until the temperature at the still headremained about at least 105° C. Then toluene was essentially the onlyvolatile component in the reaction mixture. The reaction mixture wasthen neutralized with sodium bicarbonate and the toluene was removed bydistillation the residue was then filtered to remove residual sodiumbicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 1000 cs., said blockcopolyer consisting essentially of about 19.5 percent by weight ofpolysiloxane blocks and about 80.5 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 4

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 162 g. of a polyether admixture having anaverage molecular weight of about 2,100 and consisting of about 78percent by weight of monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1900wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution and about 22 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 75 g. oftoluene; (3) about 0.6 g. of trifluoroacetic acid catalyst, about 0.28g. of potassium acetate cocatalyst; and (4) about 40 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO, and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to aone-liter, agitated, glass reaction vessel fitted with a distillationcolumn and still head. The reaction mixture was heated to reflux.Ethanol was removed at the still head operated at a partial reflux as atoluene-ethanol azeotrope until the temperature at the still headremained about at least 105° C. Then toluene was essentially the onlyvolatile component in the reaction mixture. The reaction mixture wasthen neutralized with sodium bicarbonate and the toluene was removed bydistillation the residue was then filtered to remove residual sodiumbicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 1000 cs., said blockcopolymer consisting essentially of about 19.5 percent by weight ofpolysiloxane blocks and about 80.5 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 5

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 162 g. of a polyether admixture having anaverage molecular weight of about 2100 and consisting of about 78percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1900wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution and about 22 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 2.0 g. ofpyridinium dodecylbenzenesulfonate catalyst (C₅ H₅ NH+C₁₂ H₂₅ C₆ H₄ SO₃⁻); and about 40 g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 2 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 1000 cs., said block copolymer consisting essentially of about19.5 percent by weight of polysiloxane blocks and about 80.5 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 6

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 105 g. of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 2800 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about 57 g.of toluene; (3) about 0.5 cc. of chloroplatinic acid catalyst (10%solution in 1,2-dimethoxy ethane), and (4) about 27 g. of anequilibrated trimethyl endblocked poly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluid consisting essentially of about 5.1siloxy units of the formula (Me)(H)SiO, about 72 siloxy units of theformula Me₂ SiO and about 2 siloxy units of the formula (Me)₃ SiO₀.5 peraverage molecule (about 6.4 percent of the total siloxy units being(Me)(H)SiO) to a one liter, agitated, glass reaction vessel fitted witha still head. The reaction mixture was heated to 80° C.-90° C. and helduntil silanic hydrogen was no longer detectable by reaction with anethanol solution of potassium hydroxide. The toluene was removed bydistillation and the residue filtered. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 3400 cs., said blockcopolymer consisting essentially of about 25.1 percent by weight ofpolysiloxane blocks and about 74.9 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of the blockcopolymer are shown below.

EXAMPLE 7

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 105 g. of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 2800 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about 0.5cc. of chloroplatinic acid catalyst (10% solution in 1,2-dimethoxyethane), and (3) about 27g. of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 5.1 siloxy units of the formula(Me)(H)SiO, about 72 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 6.4percent of the total siloxy units being (Me)(H) SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a hazy liquid, said block copolymer consistingessentially of about 25.1 percent by weight of polysiloxane blocks andabout 74.9 percent by weight of polyoxyalkylene blocks. The polyurethanefoam stabilizing properties of the block copolymer are shown below.

EXAMPLE 8

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 200 g. of a polyether admixture having anaverage molecular weight of about 1560 and consisting of about 50percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 50 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 1.8 g. ofpyridinium dodeylbenzenesulfonate catalyst; and (3) about 72 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5 , about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 24.7 percent by weight of polysiloxane blocks and about 75.3percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 9

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 60 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium doceylbenzenesulfonate catalyst and (3) about 32 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 22.8 percent by weight of polysiloxane blocks and about 77.2percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 10

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 150 g. of a polyether admixture having anaverage molecular weight of about 1600 and consisting of about 47percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 53 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 1.2 g. ofpyridinium doceylbenzenesulfonate catalyst; and (3) about 52 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5 , about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 1060 cs., said blockcopolymer consisting essentially of about 24.3 percent by weight ofpolysiloxane blocks and about 75.7 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 11

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 150 g. of a polyether admixture having anaverage molecular weight of about 1630 and consisting of about 45percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 55 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 1.2 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 51 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 23.7 percent by weight of polysiloxane blocks and about 76.3percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 12

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 150 g. of a polyether admixture having anaverage molecular weight of about 1480 and consisting of about 55percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 45 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 1.2 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 57 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5 , about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 26.8 percent by weight of polysiloxane blocks and about 73.2percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 13

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1600 and consisting of about 47percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 53 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.6 g. of apyridinium dodecylbenzenesulfonate catalyst; and (3) about 31 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.8 siloxy units of the formula MeSiO₁.5, about20.2 siloxy units of the formula Me₂ SiO and about 3.8 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.7percent of the total siloxy units being (Me)₂ (OC₂ H₅) SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 22.1 percent by weight of polysiloxane blocks and about 77.9percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 14

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1600 and consisting of about 47percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 53 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.6 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 33 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 2.0 siloxy units of the formula MeSiO₁.5 , about22.6 siloxy units of the formula Me₂ SiO and about 4.0 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 13.9percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 23.4 percent by weight of polysiloxane blocks and about 76.6percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 15

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1600 and consisting of about 47percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 53 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 1.0 g. of apyridinium dodecylbenzenesulfonate catalyst; and (3) about 34 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 1.4 siloxy units of the formula MeSiO₁.5, about19.7 siloxy units of the formula Me₂ SiO and about 3.4 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.6percent of the total siloxy units being (Me)₂ (OC₂ H₅) SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 23.6 percent by weight of polysiloxane blocks and about 76.4percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 16

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1600 and consisting of about 47percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 53 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 1.0 g. ofpyridinium dodecylbenzenesulfonate catalyst, and (3) about 37 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 2.5 siloxy units of the formula MeSiO₁.5 , about29.3 siloxy units of the formula Me₂ SiO and about 4.5 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 12.4percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 25.6 percent by weight of polysiloxane blocks and about 74.4percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer products are shown below.

EXAMPLE 17

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1600 and consisting of about 47percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 53 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 34 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 1.4 siloxy units of the formula MeSiO₁.5, about20.2 siloxy units of the formula Me₂ SiO and about 3.4 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 13.6percent of the total siloxy units being (Me)₂ (OC₂ H₅) SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 24.0 percent by weight of polysiloxane blocks and about 76.0percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 18

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1600 and consisting of about 47percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 53 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxyproplene, sad oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 32 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5 , about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 15.3percent of the total siloxy units being (Me)₂ (OC₂ H₅) SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 22.8 percent by weight of polysiloxane blocks and about 77.2percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 19

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1600 and consisting of about 47percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 53 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 37 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 2.5 siloxy units of the formula MeSi0₁.5, about29.5 siloxy units of the formula Me₂ SiO and about 4.5 siloxy units ofthe formula (Me)₂ (OC₂ H₅)Si0₀.5 per average molecule (about 12.3percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 25.7 percent by weight of polysiloxane blocks and about 74.3percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 20

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1480 and consisting of about 55percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 45 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 35 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 1.8 siloxy units of the formula MeSiO₁.5 about 20.2siloxy units of the formula Me₂ SiO and about 3.8 siloxy units of theformula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.7 percent ofthe total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a one liter,agitated, glass reaction vessel fitted with a still head and a tubeextending to near the bottom of the vessel. The reaction mixture washeated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 23.9 percent by weight of polysiloxane blocks and about 76.1percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 21

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1480 and consisting of about 55percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 45 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 37g. of anequilibrated ethoxy and blocked polydimethylsiloxane fluid consistingessentially of about 2.0 siloxy units of the formula MeSiO₁.5, about22.6 siloxy units of the formula Me₂ SiO and about 4.0 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO.sub. 0.5 per average molecule (about 14.0percent of the total siloxy units being (Me)₂ (0C₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 25.2 percent by weight of polysiloxane blocks and about 74.8percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 22

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1480 and consisting of about 55percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 45 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 41 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 2.5 siloxy units of the formula MeSiO₁.5, about29.3 siloxy units of the formula Me₂ SiO and about 4.5 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 12.4percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 27.6 percent by weight of polysiloxane blocks and about 72.4percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 23

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1480 and consisting of about 55percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 45 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 38 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 1.4 siloxy units of the formula MeSiO₁.5 about 20.2siloxy units of the formula Me₂ SiO and about 3.4 siloxy units of theformula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 13.6 percent ofthe total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a one liter,agitated, glass reaction vessel fitted with a still head and a tubeextending to near the bottom of the vessel. The reaction mixture washeated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 25.9 percent by weight of polysiloxane blocks and about 74.1percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 24

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 60percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 40 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. of apyridinium dodecylbenzenesulfonate catalyst; and (3) about 31 g. of anequilibrated ethoxy end blocked polydimethylsiloxane fluid consistingessentially of about 1.4 siloxy units of the formula MeSiO.sub. 1.5,about 19.7 siloxy units of the formula Me₂ SiO and about 3.4 siloxyunits of the formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about14.6 percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to aone liter, agitated, glass reaction vessel fitted with a still head anda tube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 21.6 percent by weight of polysiloxane blocks and about 78.4percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 25

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 60 percent by weight of a monohydroxy terminatedpolyoxyalkylene butanol started copolymer having an average molecularweight of about 3200 wherein about 50 weight percent of the oxyalkylenegroups of the copolymer are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene, said oxyalkylene groups presentin the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 29 g. of anequilibrated ethoxy endblocked, polydimethylsiloxane fluid consistingessentially of about 1.8 siloxy units of the formula MeSiO₁.5, about20.2 siloxy units of the formula Me₂ SiO and about 3.8 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.7percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 20.7 percent by weight of polysiloxane blocks and about 79.3percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 26

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 60 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 30 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 2.0 siloxy units of the formula MeSiO₁.5 , about22.6 siloxy units of the formula Me₂ SiO and about 4.0 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 13.9percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 21.9 percent by weight of polysiloxane blocks and about 78.1percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 27

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 60 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 34 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 2.5 siloxy units of the formula MeSiO₁.5, about29.3 siloxy units of the formula Me₂ SiO and about 4.5 siloxy units ofthe formula (Me)₂ (OC₂ H₅) SiO₀.5 per average molecule (about 12.4percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 24.1 percent by weight of polysiloxane blocks and about 75.9percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 28

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 60 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 32 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.4 siloxy units of the formula MeSiO₁.5 , about20.2 siloxy units of the formula Me₂ SiO and about 3.4 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 13.6percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 22.5 percent by weight of polysiloxane blocks and about 77.5percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product was shown below.

EXAMPLE 29

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 60 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst, and (3) about 30 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 15.3percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualbicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 21.3 percent by weight of polysiloxane blocks and about 78.7percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 30

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 60 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.8 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 31 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 1200 cs., said blockcopolymer consisting essentially of about 22.3 percent by weight ofpolysiloxane blocks and about 77.7 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 31

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 158 g. of a polyether admixture having anaverage molecular weight of about 1870 and consisting of about 34percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 66 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a ramdon distribution; (2) about 1.0 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 41 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene block copolymer product was ahomogeneous liquid, said block copolymer consisting essentially of about20.5 percent by weight of polysiloxane block and about 79.5 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 32

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 130 g. of a polyether admixture having anaverage molecular weight of about 2650 and consisting of about 50percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1750 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; and about 50 percent by weight of a monomethoxyterminated allyl alcohol started polyoxyalkylene copolymer having anaverage molecular weight of about 2950 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; (2)about 0.11 cc. of chloroplatinic acid catalyst (10% solution in1,2-dimethoxy ethane) and (3) about 28.5 g. of an equilibrated trimethylendblocked poly(dimethylsiloxymethylhydrogen siloxy) siloxane copolymerfluid consisting essentially of about 17.5 siloxy units of the formula(Me)(H)SiO, about 130 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about10.9 percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80°-90° C. and held until silanic hydrogen was nolonger detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about990 cs., said block copolymer consisting essentially of about 22.2percent by weight of polysiloxane blocks and about 77.8 percent byweight of polyoxyalkylene blocks. The polyurethane foam stablizingproperties of the block copolymer are shown below.

EXAMPLE 33

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2350 and consisting of 25 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1000 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 75 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 4050 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about 0.11cc. of chloroplatinic acid catalyst (10% solution in 1,2-dimethoxyethane) and (3) about 34 g. of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 3.2 siloxy units of the formula(Me)(H)SiO, about 32.8 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 8.4percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80°-90° C. and held until silanic hydrogen was nolonger detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about930 cs., said block copolymer consisting essentially of about 25.4percent by weight of polysiloxane blocks and about 74.6 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 34

A polyxiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2350 and consisting of 25 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1000 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 75 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 4050 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about 0.11cc. of chloroplatinic acid catalyst (10% solution in 1,2-dimethoxyethane) and (3) about 36 g. of an equilibrated trimethyl endblockedpoly(dimethylsiloxymethylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 4.2 siloxy units of the formula(Me)(H)SiO, about 44.7 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 8.3percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80°-90° C. and held until silanic hydrogen was notlonger detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1360 cs., said block copolymer consisting essentially of about 26.4percent by weight of polysiloxane blocks and about 73.6 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 35

A polysiloxane-polyl(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2350 and consisting of 25 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1000 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 75 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 4050 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about 0.11cc. of chloroplatinic acid catalyst (10% solution in 1,2-dimethoxyethane) and (3) about 36 g. of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 6.3 siloxy units of the formula(Me)(H)SiO, about 62.7 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 8.9percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about2030 cs., said block copolymer consisting essentially of about 26.4percent by weight of polysiloxane blocks and about 73.6 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 36

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2350 and consisting of 25 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1000 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 75 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 4050 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about 0.11cc. of chloroplatinic acid catalyst (10% solution in 1,2-dimethoxyethane) and (3) about 36.2 g. of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 13.7 siloxy units of the formula(Me)(H)SiO, about 135.5 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 8.4percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanichydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about3420 cs., said block copolymer consisting essentially of about 26.4precent by weight of polysiloxane blocks and about 73.6 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 37

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 130 g. of a polyether admixture having anaverage molecular weight of about 1610 and consisting of 25 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 570 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 75 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 4050 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution, (2) about 0.11cc. of chloroplatinic acid catalyst (10% solution in 1,2-dimethoxyethane) and (3) about 34 g. of an equilibrated trimethyl end blockedpoly(dimethylsiloxymethylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 9.9 siloxy units of the formula(Me)(H)SiO, about 64.6 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about13.0 percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1170 cs., said block copolymer consisting essentially of about 25.9percent by weight of polysiloxane blocks and about 74.1 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 38

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 126 g. of a polyether admixture having anaverage molecular weight of about 1700 and consisting of about 33percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1000 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 33 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 1750 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 34 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane); and (3 ) about 32g. of an equilibrated trimethyl endblockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 9.9 siloxy units of the formula(Me)(H)SiO, about 64.6 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about12.9 percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about840 cs., said block copolymer consisting essentially of about 24.3percent by weight of polysiloxane blocks and about 75.7 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 39

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 126 g. of a polyether admixture having anaverage molecular weight of about 1700 and consisting of about 33percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1000 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 33 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 1750 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 34 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane); and (3) about 33g. of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 19.8 siloxy units of the formula(Me)(H)SiO about 130 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about13.0 percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1220 cs., said block copolymer consisting essentially of about 24.8percent by weight of polysiloxane blocks and about 75.2 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 40

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 1640 and consisting of about 20percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about570 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 20 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 2950 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 60 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2)about 0.11 cc. of thechloroplatinic acid catalyst (10% solution in 1,2-dimethoxy ethane); and(3) about 31 g. of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) copolymer fluid consistingessentially of about 9.9 siloxy units of the formula (Me)(H)SiO, about64.6 siloxy units of the formula Me₂ SiO and about 2 siloxy units of theformula (Me)₃ SiO₀.5 per average molecular (about 12.9 percent of thetotal siloxy units being (Me)(H)SiO) to a one liter, agitated, glassreaction vessel fitted with a still head. The reaction mixture washeated to 80° C.-90° C. and held until silanic hydrogen was no longerdetectable by reaction with an ethanol solution of potassium hydroxide.The polysiloxane-poly(oxyethylene-oxyproplyene) block copolymer productwas a homogeneous liquid having a viscosity of about 1010 cs., saidblock copolymer consisting essentially of about 23.6 percent by weightof polysiloxane blocks and about 76.4 percent by weight ofpolyoxyalkylene blocks. The polyurethane foam stabilizing properties ofthe block copolymer are shown below.

EXAMPLE 41

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 1640 and consisting of about 20percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about570 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, about 20 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 2950 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 60 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane); and (3) about 32g. of an equilibrated trimethyl endblockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 19.8 siloxy units of the formula(Me(H)SiO, about 130 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about13.0 percent of the total siloxy unit is being (Me)(H)SiO) to a oneliter, agitated, glass reaction vessel fitted with a still head. Thereaction mixture was heated to 80° C.-90° C. and held until silanichydrogen was no longer detectable by reaction with an ethanol solutionof potassium hydroxide. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 1490 cs., said block copolymer consisting essentially of about24.2 percent by weight of polysiloxane blocks and about 75.7 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 42

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2200 and consisting of about 20percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1000 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 20 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 1750 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 60 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane); and (3) about 31.5g. of an equilibrated trimethyl endblockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 7.5 siloxy units of the formula(Me)(H)SiO, about 67 siloxy units of the formula Me.sub. 2 SiO and about2 siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about9.8 percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1250 cs., said block copolymer consisting essentially of about 23.9percent by weight of polysiloxane blocks and about 76.1 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 43

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2200 and consisting of about 20percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1000 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 20 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 1750 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 60 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane); and (3) about 38.5g. of an equilibrated trimethyl endblockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 4.2 siloxy units of the formula(Me)(H)SiO, about 44.7 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 8.3percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1210 cs., said block copolymer consisting essentially of about 27.9percent by weight of polysiloxane blocks and about 72.1 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 44

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2200 and consisting of about 20percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1000 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 20 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 1750 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 60 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane); and (3) about 38.5g. of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 6.3 siloxy units of the formula(Me)(H)SiO, about 67.7 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (8.3percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1680 cs., said block copolymer consisting essentially of about 27.9percent by weight of polysiloxane blocks and about 72.1 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 45

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2200 and consisting of about 20percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1000 wherein about 40 weight percent of the oxyalkylene groups of thecopolymers are oxyethylene, the remainder of of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; about 20 percent by weight of amonomethoxy terminated polyoxyalkylene allyl alcohol started copolymerhaving an average molecular weight of about 1750 wherein about 40 weightpercent of the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 60 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane); and (3) about 38.6g. of an equilibrated trimethyl endblockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 12.7 siloxy units of the formula(Me)(H)SiO, about 135.5 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 8.5percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about2500 cs., said block copolymer consisting essentially of about 27.8percent by weight of polysiloxane blocks and about 72.2 percent byweight of polyoxyalkylene blocks. The polyurethane foaming stabilizingproperties of the block copolymer are shown below.

EXAMPLE 46

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 122 g. of a polyether admixture having anaverage molecular weight of about 2460 and consisting of about 15percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1000 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 15 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 1750 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution and about70 percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about4050 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; (2) about 0.11 cc. of chloroplatinic acidcatalyst (10% solution in 1,2-dimethoxy ethane); and (3) about 48 g. ofan equilibrated trimethyl endblockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 5.1 siloxy units of the formula(Me)(H)SiO, about 72 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 6.4percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about3500 cs., said block copolymer consisting essentially of about 32.4percent by weight of polysiloxane blocks and about 67.6 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 47

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 2270 and consisting of about 25percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 75 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3800 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.6 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 28.5 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 4.0 siloxy units of the formula MeSiO₁.5 , about38.0 siloxy units of the formula Me₂ SiO and about 6.0 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 12.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 4800 cs., said blockcopolymer consisting essentially of about 21.3 percent by weight ofpolysiloxane blocks and about 78.7 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 48

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 30 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 30 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.8g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 31g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecular (about 14.5 percent of the total siloxy unitsbeing (Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reactionvessel fitted with a still head and a tube extending to near the bottomof the vessel. The reaction mixture was heated to 135°-145° C. withnitrogen being fed through the subnatent tube. The reaction was carriedout for about 2 hours with ethanol being removed at the still head. Thereaction mixture was then neutralized with sodium bicarbonate and theresidue filtered to remove residual sodium bicarbonate and the saltformed in the neutralization. The polysiloxane-poly(oxyethylene-oxypropylene) block copolymer product was a homogeneousliquid having a viscosity of about 2070 cs., said block copolymerconsisting essentially of about 22.1 percent by weight of polysiloxaneblocks and about 77.9 percent by weight of polyoxyalkylene blocks. Thepolyurethane foam stabilizing properties of said block copolymer productare shown below.

EXAMPLE 49

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 30 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 30 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) and 0.8g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 34g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 4.0 siloxyunits of the formula MeSiO₁.5, about 38 siloxy units of the formula Me₂SiO and about 6 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5 peraverage molecule (about 12.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅) SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 2 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 2090 cs., said block copolymer consisting essentially of about23.7 percent by weight of polysiloxane blocks and about 76.3 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 50

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100g. of a polyether admixture having anaverage molecular weight of about 1770 and consisting of about 35percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 30 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 35 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) and 0.8g. pyridinium dodecylbenzenesulfonate catalyst;and (3) about 31g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 4 siloxyunits of the formula MeSiO₁.5, about 54.8 siloxy units of the formulaMe₂ SiO and about 6 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5 peraverage molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 2 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly (oxyethlene-oxypropylene)block copolymer product was a homogeneous liquid, said block copolymerconsisting essentially of about 22.1 percent by weight of polysiloxaneblocks and about 77.9 percent by weight of polyoxyalkylene blocks. Thepolyurethane foam stabilizing properties of said block copolymer productare shown below.

EXAMPLE 51

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100g. of a polyether admixture having anaverage molecular weight of about 1770 and consisting of about 35percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 30 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 35 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.8g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 34g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 4 siloxyunits of the formula MeSiO₁.5, about 38 siloxy units of the formula Me₂SiO and about 6 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5 peraverage molecule (about 12.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom vessel.The reaction mixture was heated to 135°-145° C. with nitrogen being fedthrough the subnatent tube. The reaction was carried out for about 2hours with ethanol being removed at the still head. The reaction mixturewas then neutralized with sodium bicarbonate and the residue filtered toremove residual sodium bicarbonate and the salt formed in theneutralization. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid, said block copolymerconsisting essentially of about 23.7 percent by weight of polysiloxaneblocks and about 76.3 percent by weight of polyoxyalkylene blocks. Thepolyurethane foam stabilizing properties of said block copolymer productare shown below.

EXAMPLE 52

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 1870 and consisting of about 35percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 35 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 30 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.8g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 35g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO peraverage molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅) SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 2 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid, said block copolymerconsisting essentially of about 21.2 percent by weight of polysiloxaneblocks and about 78.8 percent by weight of polyoxyalkylene blocks. Thepolyurethane foam stabilizing properties of said block copolymer productare shown below.

EXAMPLE 53

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 1980 and consisting of about 33.4percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 33.3 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 33.3percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 3800wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; (2) about 0.8g of pyridiniumdodecylbenzenesulfonate catalyst; and (3) about 33g. of an equilibratedethoxy endblocked polydimethylsiloxane fluid consisting essentially ofabout 1.3 siloxy units of the formula MeSiO₁.5, about 18.2 siloxy unitsof the formula Me₂ SiO and about 3.3 siloxy units of the formula (Me)₂(OC₂ H₅)SiO₀.5 per average molecule (about 14.5 percent of the totalsiloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glassreaction vessel fitted with a still head and a tube extending to nearthe bottom vessel. The reaction mixture was heated to 135° -145° C. withnitrogen being fed through the subnatent tube. The reaction was carriedout for about 2 hours with ethanol being removed at the still head. Thereaction mixture was then neutralized with sodium bicarbonate and theresidue filtered to remove residual sodium bicarbonate and the saltformed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 2610 cs., said blockcopolymer consisting essentially of about 20.3 percent by weight ofpolysiloxane blocks and about 79.7 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 54

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 1770 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 20 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 40 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxyalkylenegroups being oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.8g. of pyridiniumdodecylbenzenesulfonate catalyst; and (3) about 37g. of an equilibratedethoxy end blocked polydimethylsiloxane fluid consisting essentially ofabout 1.3 siloxy units of the formula MeSiO₁.5, about 18.2 siloxy unitsof the formula Me₂ SiO and about 3.3 siloxy units of the formula (Me)₂(OC₂ H₅)SiO₀.5 per average molecule (about 14.5 percent of the totalsiloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glassreaction vessel fitted with a still head and a tube extending to nearthe bottom of the vessel. The reaction mixture was heated to 135° -145°C. with nitrogen being fed through the subnatent tube. The reaction wascarried out for about 4 hours with ethanol being removed at the stillhead. The reaction mixture was then neutralized with sodium bicarbonateand the residue filtered to remove residual sodium bicarbonate and thesalt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 2430 cs., said blockcopolymer consisting essentially of about 22.1 percent by weight ofpolysiloxane blocks and about 77.9 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 55

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 1950 and consisting of about 30percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 35 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 35 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.8g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 34g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135° -145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid, said block copolymerconsisting essentially of about 20.5 percent by weight of polysiloxaneblocks and about 79.5 percent by weight of polyoxyalkylene blocks. Thepolyurethane foam stabilizing properties of said block copolymer productare shown below.

EXAMPLE 56

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 1700 and consisting of about 36percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 40 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 24 percentby weight of a monohydroxy terminated polyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 1.0g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 36.5 g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO.sub.0.5 per average molecule (about 14.5 percent of the total siloxy unitsbeing (Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reactionvessel fitted with a still head and a tube extending to near the bottomof the vessel. The reaction mixture was heated to 135° -145° C. withnitrogen being fed through the subnatent tube. The reaction was carriedout for about 4 hours with ethanol being removed at the still head. Thereaction mixture was then neutralized with sodium bicarbonate and theresidue filtered to remove residual sodium bicarbonate and the saltformed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 2290 cs., said blockcopolymer consisting essentially of about 21.7 percent by weight ofpolysiloxane blocks and about 78.3 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 57

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 1830 and consisting of about 30percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 40 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 30 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.8g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 36g. of an equilibrated ethoxy end blockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the Me₂ SiOand about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5 peraverage molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135° -145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 2260cs., said block copolymer consisting essentially of about 21.5percent by weight of polysiloxane blocks and about 78.5 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 58

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 1520 and consisting of about 45percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 20 percent by weight of monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 35 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.8g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 38.5g. of an equilibrated ethoxy end blockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.3 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135° -145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neturalization. The polysiloxane-poly (oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 1650cs., said block copolymer consisting essentially of about 24.7percent by weight of polysiloxane blocks and about 75.3 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 59

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 1630 and consisting of about 35percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 20 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 45 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 1.0g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 36.7g. of an equilibrated ethoxy end blockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135° -145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly (oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 2760cs., said block copolymer consisting essentially of about 21.8percent by weight of polysiloxane blocks and about 78.2 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 60

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 1610 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 25 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 35 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.8g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 37g. of an equilibrated ethoxy end blockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy unit being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselwith a still head and a tube extending to near the bottom of the vessel.The reaction mixture was heated to 135° -145° C. with nitrogen being fedthrough the subnatent tube. The reaction was carried out for about 4hours with ethanol being removed at the still head. The reaction mixturewas then neutralized with sodium bicarbonate and the residue filtered toremove residual sodium bicarbonate and the salt formed in theneutralization. The polyxiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about2010cs., said block copolymer consisting essentially of about 22.0percent by weight of polysiloxane blocks and about 78.0 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 61

A polysiloxane-poly (oxyethylene-oxyproplyene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 1910 and consisting of about 30percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 25 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 45 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.8g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 31g. of an equilibrated ethoxy end blockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135° -145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homegeneous liquid having a viscosity ofabout 2850cs., said block copolymer consisting essentially of about 19.2percent by weight of polysiloxane blocks and about 80.7 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 62

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 1700 and consisting of about 30percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 30 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, and oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 40 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.8g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 31g. of an equilibrated ethoxy end blockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me) (OC₂ H₂)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly (oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 2700cs., said block copolymer consisting essentially of about 19.2percent by weight of polysiloxane blocks and about 80.7 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 63

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 35percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 40 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 25 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.7g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 30.2g. of an equilibrated ethoxy endblockedpolymethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5 about 18.2 siloxy units of the formula Me₂SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5 peraverage molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-ocypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 2150cs., said block copolymer consisting essentially of about 21.7percent by weight of polysiloxane blocks and about 78.3 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 64

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100g. of a polyether admixture having anaverage molecular weight of about 1630 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 25 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 35 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.7g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 32g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 2140cs., said block copolymer consisting essentially of about 22.5percent by weight of polysiloxane blocks and about 77.5 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 65

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 165g. of a polyether admixture having anaverage molecular weight of about 1740 and consisting of about 30percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 20 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 1900 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 50 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.7g. of pyridinium dodecylbenzenzsulfonatecatalyst; and (3) about 43g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 2140cs., said block copolymer consisting essentially of about 20.5percent by weight of polysiloxane blocks and about 79.5 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 66

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 165g. of a polyether admixture having anaverage molecular weight of about 1610 and consisting of about 35percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 25 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 1900 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 40 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.7g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 47g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.3 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 1460cs., said block copolymer consisting essentially of about 21.9percent by weight of polysiloxane blocks and about 78.1 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 67

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 165g. of a polyether admixture having anaverage molecular weight of about 1630 and consisting of about 30percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 35 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 1900 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 35 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.7g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 46g. of an equilibrated ethoxy endblockedpolydimethlsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (14.5 percent of the total siloxy units being (Me)₂(OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vessel fittedwith a still head and a tube extending to near the bottom of the vessel.The reaction mixture was heated to 135°-145° C. with nitrogen being fedthrough the subnatent tube. The reaction was carried out for about 4hours with ethanol being removed at the still head. The reaction mixturewas then neutralized with sodium bicarbonate and the residue filtered toremove residual sodium bicarbonate and the salt formed in theneutralization. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1470 cs., said block copolymer consisting essentially of about 21.5percent by weight of polysiloxane blocks and about 78.5 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 68

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 2350 and consisting of 25 percent byweight of a monomethoxy terminated polyoxalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1000 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 75 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 4050 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about0.11cc. of chloroplatinic acid catalyst (10% solution in 1,2-dimethoxyethane); and (3) about 36 g. of an equilibrated trimethyl endblockedpoly (dimethylsiloxy-methylhydrogensiloxy)siloxane copolymer fluidconsisting essentially of about 12.7 siloxy units of the formula(Me)(H)SiO, about 135.5 siloxy units of the formula Me₂ SiO, and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 8.4percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was homogeneous liquid having a viscosity of about3420 cs., said block copolymer consisting essentially of about 26.7percent by weight of polysiloxane blocks and about 73.3 percent byweight of polyoxalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 69

A polyxiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120g. of a polyether admixture having anaverage molecular weight of about 2350 and consisting of about 25percent by weight of a monoallyloxy terminated butanol startedpolyoxalkylene copolymer having an average molecular weight of about1000 wherein about 50 weight percent of the oxyalkylene groups areoxyethylene, the remainder of the oxalkylene groups oxypropylene, saidoxalkylene groups being present in the copolymer in a randomdistribution, and about 75 percent by weight of a monoallyloxyterminated polyoxalkylene butanol started copolymer having an averagemolecular weight of about 4050 and wherein about 50 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxalkylene groupsbeing present in the copolymer in a random distribution; (2) about 84 g.of toluene; (3) about 0.11 cc. of chloroplatinic acid catalyst (10%solution in 1,2-dimethoxyethane) of an equilibrated trimethyl endblockedpoly (dimethylsiloxy-methylhydroxensiloxy)siloxane copolymer fluidconsisting essentially of about 12.7 siloxy units of the formula(Me)(H)SiO, about 135.5 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 8.4percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head.

The reaction mixture was heated to 80° C.-90° C. and held until silanichydrogen was no longer detectable by reaction with an ethanol solutionof potassium hydroxide. The toluene was removed by distillation and theresidue filtered. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1550 cs., said block copolymer consisting essentially of about 26.7percent by weight of polysiloxane blocks and about 73.3 percent byweight of polyoxalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 70

A polysiloxane-poly (oxyethylene-oxpropylene) block copolymer wasprepared by charging (1) about 100g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 40percent by weight of a monohydroxy terminated polyoxalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxalkylene groups of thecopolymer are oxyethylene the remainder of the oxyalkylene groups beingoxypropylene, said oxalkylene groups being present in the copolymer in arandom distribution, and about 30 percent by weight of a monohydroxyterminated polyoxalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxalkylene groups of the copolymer are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution and about 30 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.8g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 31g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅) SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the resiudefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 2070 cs., said block copolymer consisting essentially of about22.1 percent by weight of polysiloxane blocks and about 77.9 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 71

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 130g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 40percent by weight of a monohydroxy terminated polyoxalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight present of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 30 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 30 percentby weight of a monohydroxy terminated polyoxalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxethylene, the remainder of the oxalkylene groups being oxypropylene,said oxalkylene groups being present in the copolymer in a randomdistribution; (2) about 1.0g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 40g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 1 hour with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly (oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 1200 cs., said block copolymer consisting essentially of about22.1 percent by weight of polysiloxane blocks and about 77.9 percent byweight of polyoxalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 72

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 1770 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene being present in the copolymer in arandom distribution, and about 20 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecule weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution and about 40 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 1.0 g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 37.2 g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 2430 cs., said block copolymer consisting essentially of about23.9 percent by weight of polysiloxane blocks and about 76.1 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 73

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 108 g. of a polyether admixture having anaverage molecular weight of about 1770 and consisting of about 40percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, about 20 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; and about 40 percentby weight of a monohydroxy terminated butanol started polyoxyalkylenecopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 62 g. of toluene; (3) about 0.2 g. of pyridiniumdodecylbenzenesulfonate catalyst; and (4) about 37 g. of an equilibratedethoxy endblocked polydimethylsiloxane fluid consisting essentially ofabout 1.3 siloxy units of the formula MeSiO₁.5, about 18.2 siloxy unitsof the formula Me₂ SiO, and about 3.3 siloxy units of the formula (Me)₂(OC₂ H₅)SiO₀.5 per average molecule (about 14.5 percent of the totalsiloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a one-liter, agitated, glassreaction vessel fitted with a distillation column and still head. Thereaction mixture was heated to reflux. Ethanol was removed at the stillhead operated at a partial reflux as a toluene-ethanol azeotrope untilthe temperature at the still head remained about at least 105° C. Thentoluene was essentially the only volatile component in the reactionmixture. The reaction mixture was then neutralized with sodiumbicarbonate and the toluene was removed by distillation, the residue wasthen filtered to remove residual sodium bicarbonate and the salt formedin the neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 1700 cs., said block copolymer consisting essentially of about23.9 percent by weight of polysiloxane blocks and about 76.1 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 74

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 1950 and consisting of about 30percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 35 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 35 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 1.0 g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 33.0 g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid, said block copolymerconsisting essentially of about 20.5 percent by weight of polysiloxaneblocks and about 79.5 percent by weight of polyoxyalkylene blocks. Thepolyurethane foam stabilizing properties of said block copolymer productare shown below.

EXAMPLE 75

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 1950 and consisting of about 30percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, about 35 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 35 percentby weight of a monohydroxy terminated butanol started polyoxyalkylenecopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 105 g. of toluene; (3) about 0.7 g. ofpyridinium dodecylbenzenesulfonate catalyst; and (4) about 33 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO, and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to aone-liter, agitated, glass reaction vessel fitted with a distillationcolumn and still head. The reaction mixture was heated to reflux.Ethanol was removed at the still head operated at a partial reflux as atoluene-ethanol azeotrope until the temperature at the still headremained about at least 105° C. The toluene was essentially the onlyvolatile component in the reaction mixture. The reaction mixture wasthen neutralized with sodium bicarbonate and the toluene was removed bydistillation, the residue was then filtered to remove residual sodiumbicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 3400 cs., said blockcopolymer consisting essentially of about 20.5 percent by weight ofpolysiloxane blocks and about 79.5 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 76

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 165 g. of a polyether admixture having anaverage molecular weight of about 1610 and consisting of about 35percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 25 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 1900 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 40 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.7 g. of pyridinium doceylbenzenesulfonatecatalyst; and (3) about 46.7 g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 1460 cs., said block copolymer consisting essentially of about21.9 percent by weight of polysiloxane blocks and about 78.1 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 77

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 165 g. of a polyether admixture having anaverage molecular weight of about 1610 and consisting of about 35percent of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 1000 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxypropylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, about 25 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 1900 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; and about 40 percentby weight of a monohydroxy terminated butanol started polyoxyalkylenecopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomfashion; (2) about 90 g. of toluene; (3) about 0.6 g. of pyridiniumdodecylbenzenesulfonate catalyst and (4) about 46.7 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO, and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecular (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to aone-liter, agitated, glass reaction vessel fitted with a distillationcolumn and still head. The reaction mixture was heated to reflux.Ethanol was removed at the still head operated at a partial reflux as atoluene-ethanol azeotrope until the temperature at the still headremained about at least 105° C. Then toluene was essentially the onlyvolatile component in the reaction mixture. The reaction mixture wasthen neutralized with sodium bicarbonate and the toluene was removed bydistillation, the residue was then filtered to remove residual sodiumbicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 1150 cs., said blockcopolymer consisting essentially of about 21.9 percent by weight ofpolysiloxane blocks and about 78.1 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 78

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 165 g. of a polyether admixture having anaverage molecular weight of about 1630 and consisting of about 35percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 30 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 1900 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution, and about 35 percentby weight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.7 g. of pyridinium dodecylbenzenesulfonatecatalyst; and (3) about 45.8 g. of an equilibrated ethoxy endblockedpolydimethylsiloxane fluid consisting essentially of about 1.3 siloxyunits of the formula MeSiO₁.5, about 18.2 siloxy units of the formulaMe₂ SiO and about 3.3 siloxy units of the formula (Me)₂ (OC₂ H₅)SiO₀.5per average molecule (about 14.5 percent of the total siloxy units being(Me)₂ (OC₂ H₅)SiO₀.5) to a one-liter, agitated, glass reaction vesselfitted with a still head and a tube extending to near the bottom of thevessel. The reaction mixture was heated to 135°-145° C. with nitrogenbeing fed through the subnatent tube. The reaction was carried out forabout 4 hours with ethanol being removed at the still head. The reactionmixture was then neutralized with sodium bicarbonate and the residuefiltered to remove residual sodium bicarbonate and the salt formed inthe neutralization. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 1470 cs., said block copolymer consisting essentially of about21.5 percent by weight of polysiloxane blocks and about 78.5 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 79

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 165 g. of a polyether mixture having anaverage molecular weight of about 1630 and consisting of about 35percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, about 30 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 1900 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; and about 35 percentby weight of a monohydroxy terminated butanol started polyoxyalkylenecopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 90 g. of toluene; (3) about 0.6 of pyridiniumdodecylbenzenesulfonate catalyst; and (4) about 45.8 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO, and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅) SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to aone-liter, agitated, glass reaction vessel fitted with a distillationcolumn and still head. The reaction mixture was heated to reflux.Ethanol was removed at the still head operated at a partial reflux as atoluene-ethanol azeotrope until the temperature at the still headremained about at least 105° C. The toluene was essentially the onlyvolatile component in the reaction mixture. The reaction mixture wasthen neutralized with sodium bicarbonate and the toluene was removed bydistillation the residue was then filtered to remove residual sodiumbicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 1015 cs., said blockcopolymer consisting essentially of about 21.5 percent by weight ofpolysiloxane blocks and about 78.5 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 80

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 200 g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 35percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, about 40 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; and about 25 percentby weight of a monohydroxy terminated butanol started polyoxyalkylenecopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 46 g. of toluene; (3) about 0.5 g. of pyridiniumdodecylbenzenesulfonate catalyst and (4) about 60.4 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO, and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to aone-liter, agitated, glass reaction vessel fitted with a distillationcolumn and still head. The reaction mixture was heated to reflux.Ethanol was removed at the still head operated at a partial reflux as atoluene-ethanol azeotrope until the temperature at the still headremained about at least 105° C. Then toluene was essentially the onlyvolatile component in the reaction mixture. The reaction mixture wasthen neutralized with sodium bicarbonate and the toluene was removed bydistillation, the residue was then filtered to remove residual sodiumbicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 1630 cs., said blockcopolymer consisting essentially of about 21.5 percent by weight ofpolysiloxane blocks and about 78.5 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 81

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 200 g. of a polyether admixture having anaverage molecular weight of about 1730 and consisting of about 35percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution and about 40 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; and about 25 percentby weight of a monohydroxy terminated butanol started polyoxyalkylenecopolymer having an average molecular weight of about 3800 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 87 g. of toluene; (3) about 0.5 g. of pyridiniumdodecylbenzenesulfonate catalyst and (4) about 60.4 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO, and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to aone-liter, agitated, glass reaction vessel fitted with a distillationcolumn and still head. The reaction mixture was heated to reflux.Ethanol was removed at the still head operated at a partial reflux as atoluene-ethanol azeotrope until the temperature at the still headremained about at least 105° C. Then toluene was essentially the onlyvolatile component in the reaction mixture. The reaction mixture wasthen neutralized with sodium bicarbonate and the toluene was removed bydistillation the residue was then filtered to remove residual sodiumbicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 1650 cs., said blockcopolymer consisting essentially of about 21.5 percent by weight ofpolysiloxane blocks and about 78.5 percent by weight of polyoxyalkyleneblocks. The polyurethane form stabilizing properties of said blockcopolymer product are shown below.

EXAMPLE 82

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 162 g. of a polyether admixture having anaverage molecular weight of about 2100 and consisting of about 78percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1900wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 22 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 1.0g, ofpyridinium dodecylbenzenesulfonate catalyst; and (3) about 40 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 19.5 percent by weight of polysiloxane blocks and about 80.5percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 83

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1600 and consisting of about 47percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 53 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 1.0 g. ofpyridinium doceylbenzenesulfonate catalyst; and (3) about 41.2 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5, about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 10.4percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxane-poly(oxyethylene-oxyproplyene) block copolymer product wasa homogeneous liquid, said block copolymer consisting essentially ofabout 27.6 percent by weight of polysiloxane blocks and about 72.4percent by weight of polyoxyalkylene blocks. The polyurethane foamstabilizing properties of said block copolymer product are shown below.

EXAMPLE 84

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 150 g. of a polyether admixture having anaverage molecular weight of about 1630 and consisting of about 11.3percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 350wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 88.7 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 1.0 g. ofpyridinium doceylbenzenesulfonate catalyst; and (3) about 48 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5 , about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 4 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxanepoly(oxyethylene-oxypropylene) block copolymer product was ahomogeneous liquid, said block copolymer consisting essentially of about22.5 percent by weight of polysiloxane blocks and about 77.5 percent byweight of polyoxyalkylene glocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 85

A polysiloxane-poly (oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 100 g. of a polyether admixture having anaverage molecular weight of about 1390 and consisting of about 60percent by weight of a monohydroxy terminated polyoxyalkylene butanolstarted copolymer having an average molecular weight of about 1000wherein about 50 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution, and about 40 percent by weight of a monohydroxyterminated polyoxyalkylene butanol started copolymer having an averagemolecular weight of about 3200 wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.6 g. ofpyridinium doceylbenzenesulfonate catalyst; and (3) about 40.3 g. of anequilibrated ethoxy endblocked polydimethylsiloxane fluid consistingessentially of about 1.3 siloxy units of the formula MeSiO₁.5 , about18.2 siloxy units of the formula Me₂ SiO and about 3.3 siloxy units ofthe formula (Me)₂ (OC₂ H₅)SiO₀.5 per average molecule (about 14.5percent of the total siloxy units being (Me)₂ (OC₂ H₅)SiO₀.5) to a oneliter, agitated, glass reaction vessel fitted with a still head and atube extending to near the bottom of the vessel. The reaction mixturewas heated to 135°-145° C. with nitrogen being fed through the subnatenttube. The reaction was carried out for about 2 hours with ethanol beingremoved at the still head. The reaction mixture was then neutralizedwith sodium bicarbonate and the residue filtered to remove residualsodium bicarbonate and the salt formed in the neutralization. Thepolysiloxanepoly(oxyethylene-oxypropylene) block copolymer product was ahomogeneous liquid, said block copolymer consisting essentially of about26.9 percent by weight of polysiloxane blocks and about 73.1 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of said block copolymer product are shown below.

EXAMPLE 86

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 162 g. of a polyether admixture having anaverage molecular weight of about 2650 and consisting of 25 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1750 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 75 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 2950 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about 0.11cc. of chloroplatinic acid catalyst (10% solution in 1,2-dimethoxyethane); and (3) about 27.3 g. of an equilibrated trimethyl endblockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 14 siloxy units of the formula(Me)(H)SiO and about 134 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula Me₃ SiO₀.5 per average molecule (about 9.9percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1660 cs., said block copolymer consisting essentially of about 21.4percent by weight of polysiloxane blocks and about 78.6 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 87

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 162 g. of a polyether admixture having anaverage molecular weight of about 2650 and consisting of 25 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1750 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 75 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 2950 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about 0.11cc. of chloroplatinic acid catalyst (10% solution in1,2-dimethoxyethane) and (3) about 27.3 g. of an equilibrated trimethylendblocked poly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymerfluid consisting essentially of about 7.5 siloxy units of the formula(Me)(H)SiO, about 67 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about10.9 percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about2200 cs., said block copolymer consisting essentially of about 21.4percent by weight of polysiloxane blocks and about 78.6 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 88

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2750 and consisting of about 20percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1750 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 60 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 2920 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 20 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane) and (3) about 51 g.of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy)siloxane copolymer fluidconsisting essentially of about 7.6 siloxy units of the formula(Me)(H)SiO, about 140 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 5.1percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about12000 cs., said block copolymer consisting essentially of about 33.7percent by weight of polysiloxane blocks and about 66.3 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 89

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2900 and consisting of 50 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1750 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 50 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 4050 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about 0.11cc. of chloroplatinic acid catalyst (10% solution in 1,2-dimethoxyethane) and (3) about 34 g. of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 4.2 siloxy units of the formula(Me)(H)SiO, about 43.9 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 8.4percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1140 cs., said block copolymer consisting essentially of about 25.4percent by weight of polysiloxane blocks and about 74.6 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 90

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2900 and consisting of 50 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1750 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 50 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 4050 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about 0.11cc. of chloroplatinic acid catalyst (10% solution in 1,2-dimethoxyethane) and (3) about 34 g. of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 6.3 siloxy units of the formula(Me)(H)SiO, about 67.7 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 8.3percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1530 cs., said block copolymer consisting essentially of about 25.3percent by weight of polysiloxane blocks and about 74.7 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 91

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2750 and consisting of about 20percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1750 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 60 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 2950 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 20 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane) and (3) about 36 g.of an equilibrated trimethyl endblockedpoly(dimethylsiloxymethylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 2.5 siloxy units of the formula(Me)(H)SiO, about 34.3 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 6.6percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1150 cs., said block copolymer consisting essentially of about 26.2percent by weight of polysiloxane blocks and about 73.8 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 92

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2750 and consisting of about 20percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1750 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 60 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 2950 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 20 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane) and (3) about 38 g.of an equilibrated trimethyl endblockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 5.1 siloxy units of the formula(Me)(H)SiO, about 68.8 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 6.7percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C. 90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about2530 cs., said block copolymer consisting essentially of about 27.5percent by weight of polysiloxane blocks and about 72.5 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 93

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 120 g. of a polyether admixture having anaverage molecular weight of about 2750 and consisting of about 20percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1750 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 60 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 2950 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 20 percent by weight of a monomethoxy terminated allyl alcoholstarted polyoxyalkylene copolymer having an average molecular weight ofabout 4050 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane) and (3) about 35 g.of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 10.1 siloxy units of the formula(Me)(H)SiO, about 137 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 6.8percent of the total siloxy units being (Me)(H) SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about3710 cs., said block copolymer consisting essentially of about 26.9percent by weight of polysiloxane blocks and about 73.1 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 94

A polysiloxane-poly(oxyethylene-oxypropylene copolymer was prepared bycharging (1) about 94 g. of a polyether admixture having an averagemolecular weight of about 2200 and consisting of about 20 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1000 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; about 20 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 1700 wherein about 40 weight percent of theoxyalkylene groups of the copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; and about 60 percentby weight of a mono-methoxy terminated polyoxyalkylene allyl alcoholstarted copolymer having an average molecular weight of about 4050wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; (2) about 0.19 cc. of chloroplatinic acidcatalyst (10% solution in 1,2-dimethoxy ethane), and (3) about 50 g. ofan equilibrated monochlorodimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 5.5 siloxy units of the formula(Me)(H)SiO, about 77.5 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Cl)(Me)₂ SiO₀.5 per average molecule to aone liter, agitated glass reaction vessel fitted with a still head. Thereaction mixture was heated to about 85° C. and held until silanichydrogen was no longer detectable by reaction with an ethanol solutionof potassium hydroxide. Then to the polysiloxane-polyoxyalkylene blockcopolymer product so produced was added (1) about 37 g. of a polyetheradmixture having an average molecular weight of about 1700 andconsisting of about 35 percent by weight of a monohydroxy terminatedpolyoxyalkylene butanol started copolymer having an average molecularweight of about 1000 wherein about 50 weight percent of the oxyalkylenegroups of the copolymer are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; about 40 percent byweight of a monohydroxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3200 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; and about 25 percent by weight of a monohydroxy terminatedpolyoxyalkylene butanol started copolymer having an average molecularweight of about 3800 wherein about 50 weight percent of the oxyalkylenegroups of the copolymer are oxyethylene, the remainder of theoxyalkylene groups in the copolymer being oxypropylene, and (2) about 21g. of Amberlyst A-21, a tertiary amine functional macroreticular ionexchange resin. The new reaction mixture was heated to 130° C. and heldfor 40 minutes. The product residue was then filtered to remove the ionexchange resin which was in hydrochloride form and recover the desiredpolysiloxane-poly(oxyethylene-oxypropylene) block copolymer productwhich was an homogeneous liquid having a viscosity of about 4600 cs..The polyurethane foam stabilizing properties of the block copolymer areshown below.

EXAMPLE 95

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 122 g. of a polyether admixture having anaverage molecular weight of about 2580 and consisting of about 25percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1200 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 10 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 2750 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 65 percent by weight of a monomethoxy terminated polyoxyalkyleneallyl alcohol started copolymer having an average molecular weight ofabout 4600 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc. of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane) and (3) about 25 g.of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy) siloxane copolymer fluidconsisting essentially of about 8.7 siloxy units of the formula(Me)(H)SiO, about 64 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ Sio₀.5 per average molecule to a oneliter, agitated, glass reaction vessel fitted with a still head. Thereaction mixture was heated to 80° C.-90° C. and held until silanichydrogen was no longer detectable by reaction with an ethanol solutionof potassium hydroxide. The polysiloxane-poly(oxyethylene-oxypropylene)block copolymer product was a homogeneous liquid having a viscosity ofabout 1500 cs., said block copolymer consisting essentially of about17.0 percent by weight of polysiloxane blocks and about 83.0 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 96

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 125 g. of a polyether admixture having anaverage molecular weight of about 2750 and consisting of about 20percent by weight of a monomethoxy terminated polyoxyalkylene allylalcohol started copolymer having an average molecular weight of about1200 wherein about 40 weight percent of the oxyalkylene groups of thecopolymer are oxyethylene, the remainer of the oxyalkylene groups beingoxypropylene, said oxyalkylene groups being present in the copolymer ina random distribution; about 20 percent by weight of a monomethoxyterminated polyoxyalkylene allyl alcohol started copolymer having anaverage molecular weight of about 2750 wherein about 40 weight percentof the oxyalkylene groups of the copolymer are oxyethylene, theremainder of the oxyalkylene groups being oxypropylene, said oxyalkylenegroups being present in the copolymer in a random distribution; andabout 60 percent by weight of a monomethoxy terminated allyl alcoholstarted polyoxyalkylene copolymer having an average molecular weight ofabout 4600 wherein about 40 weight percent of the oxyalkylene groups ofthe copolymer are oxyethylene, the remainder of the oxyalkylene groupsbeing oxypropylene, said oxyalkylene groups being present in thecopolymer in a random distribution; (2) about 0.11 cc of chloroplatinicacid catalyst (10% solution in 1,2-dimethoxy ethane) and (3) about 34.5gof an equilibrated trimethyl end blocked poly(dimethylsiloxymethylhydrogensiloxy)siloxane copolymer fluid consisting essentially ofabout 6.3 siloxy units of the formula (Me)(H)SiO, about 66 siloxy unitsof the formula Me₂ SiO and about 2 siloxy units of the formula (Me)₃SiO₀.5 per average molecule (about 8.4 percent of the total siloxy unitsbeing (Me)(H)Sio) to a one liter, agitated, glass reaction vessel fittedwith a still head. The reaction mixture was heated to 80°-90° C. andheld until silanic hydrogen was no longer detectable by reaction with anethanol solution of potassium hydroxide. Thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer product wasa homogeneous liquid having a viscosity of about 2290 cs., said blockcopolymer consisting essentially of about 21.6 percent by weight ofpolysiloxane blocks and about 98.4 percent by weight of polyoxyalkyleneblocks. The polyurethane foam stabilizing properties of the blockcopolymer are shown below.

EXAMPLE 97

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 250 g. of a polyether admixture having anaverage molecular weight of about 2160 and consisting of 40 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1200 wherein about40 percent of the oxyalkylene groups of the copolymer are oxyethylene,the remainder of the oxyalkylene groups being oxypropylene, saidoxyalkylene groups being present in the copolymer in a randomdistribution and about 60 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 4600 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene the remainder ofthe oxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; (2) about 0.25 cc. ofchloroplatinic acid catalyst (10% solution in 1,2-dimethoxy ethane) and(3) about 69 g. of an equilibrated trimethyl end blockedpoly(dimethylsibloxy-methylhydro-gensiloxy siloxane copolymer fluidconsisting essentially of about 14.9 siloxy units of the formula(Me)(H)SiO, about 132 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about10.0 percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80°-90° C. and held until silanic hydrogen was nolonger detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1400 cs., said block copolymer consisting essentially of about 21.6percent by weight of polysiloxane blocks and about 78.4 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 98

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 122 g. of a polyether admixture having anaverage molecular weight of about 2160 and consisting of 40 percent byweight of a monomethoxy terminated polyoxyalkylene allyl alcohol startedcopolymer having an average molecular weight of about 1200 wherein about40 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution, and about 60 percent by weight of a monomethoxy terminatedpolyoxyalkylene allyl alcohol started copolymer having an averagemolecular weight of about 4600 and wherein about 40 weight percent ofthe oxyalkylene groups of the copolymer are oxyethylene, the remainderof the oxyalkylene groups being oxypropylene, said oxyalkylene groupsbeing present in the copolymer in a random distribution; (2) about 0.11cc of chloroplatinic acid catalyst (10% solution in 1,2-dimethoxyethane)and (3) about 41.8 g. of an equilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy)siloxane copolymer fluidconsisting essentially of about 6.3 siloxy units of the formula(Me)(H)SiO, about 66 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about 8.4percent of the total siloxy units being (Me)(H)SiO) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about1400 cs., said block copolymer consisting essentially of about 25.5percent by weight of polysiloxane blocks and about 74.6 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 99

A polysiloxane-poly(oxyethylene-oxypropylene) block copolymer wasprepared by charging (1) about 366 g. of a polyether admixture having anaverage molecular weight of about 1830 and consisting of 40 percent byweight of a monoallyloxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 1000 wherein about50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; about 40 percent by weight of a monoallyloxy terminatedpolyoxyalkylene butanol started copolymer having an average molecularweight of about 3200 and wherein about 50 weight percent of theoxyalkylene groups of the copolymer are oxyethylene the remainder of theoxyalkylene groups being oxypropylene, said oxyalkylene groups beingpresent in the copolymer in a random distribution; and about 20 percentby weight of a monoallyloxy terminated polyoxyalkylene butanol startedcopolymer having an average molecular weight of about 3800 and wherein50 weight percent of the oxyalkylene groups of the copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,said oxyalkylene groups being present in the copolymer in a randomdistribution; (2) about 0.21 cc. of chloroplatinic acid catalyst (10%solution, in 1,2-dimethoxy ethane) and (3) about 105 g. of anequilibrated trimethyl end blockedpoly(dimethylsiloxy-methylhydrogensiloxy)siloxane copolymer fluidconsisting essentially of about 6.9 siloxy units of the formula(Me)(H)SiO, about 50 siloxy units of the formula Me₂ SiO and about 2siloxy units of the formula (Me)₃ SiO₀.5 per average molecule (about11.7 percent of the total siloxy units being (Me)(H)Sio) to a one liter,agitated, glass reaction vessel fitted with a still head. The reactionmixture was heated to 80° C.-90° C. and held until silanic hydrogen wasno longer detectable by reaction with an ethanol solution of potassiumhydroxide. The polysiloxane-poly(oxyethylene-oxypropylene) blockcopolymer product was a homogeneous liquid having a viscosity of about3740 cs., said block copolymer consisting essentially of about 22.2percent by weight of polysiloxane blocks and about 77.8 percent byweight of polyoxyalkylene blocks. The polyurethane foam stabilizingproperties of the block copolymer are shown below.

EXAMPLE 100

The polysiloxane-poly(oxyethylene-oxypropylene) block copolymers of theabove Examples were evaluated as foam stabilizers for flexible polyetherpolyurethane foam according to the above defined test procedures and theresults are reported in Table I below. Said results demonstrate thesuperiority of the novel polysiloxane-poly(oxyethylene-oxypropylene)block copolymers of this invention as compared topolysiloxane-poly(oxyethylene-oxypropylene) block copolymers not of theinstant invention.

                  TABLE I                                                         ______________________________________                                                           Height    Cells    Air                                     Product of                                                                              Foam     of Rise,  Per      Flow                                    Example   Test     Inches    Inch     Rate                                    ______________________________________                                         1*       I        12.6      34       6.0                                      2*       I        12.4      34       6.0                                      3*       I        11.0      30       4.0                                      4*       I                  Failed                                            5*       I                  Failed                                            6*       V        12.0      34       6.2                                      7*       V                  Failed                                            8*       I        12.0      34       7.3                                      9*       I        11.2      34       5.7                                     10*       I        11.7      34       7.3                                     11*       I        12.0      34       7.6                                     12*       I        11.4      34       7.5                                     13*       I        11.6      34       8.5                                     14*       I        11.8      34       7.8                                     15*       I        11.6      34       8.2                                     16*       I        11.4      34       6.6                                     17*       I        11.4      34       6.9                                     18*       I        11.7      34       7.3                                     19*       I        11.9      34       7.5                                     20*       I        11.3      34       8.0                                     21*       I        11.2      34       7.7                                     22*       I        11.4      34       7.7                                     23*       I        11.4      34       8.2                                     24*       I        11.9      34       7.4                                     25*       I        12.1      34       7.2                                     26*       I        12.0      34       6.5                                     27*       I        11.2      34       7.2                                     28*       I        11.9      34       7.7                                     29*       I        12.0      34       7.5                                     30*       I        11.5      32       7.4                                     31*       I        11.0      34       6.7                                     32        III      11.2      32       1.5                                     33        III      11.9      30       4.3                                     34        III      11.8      32       5.0                                     35        VI       12.0      34       5.5                                     35        V        12.5      34       3.9                                     36        VI       11.8      32       2.5                                     37        V        12.2      32       0.8                                     38        V        11.9      34       4.2                                     39        V        12.1      34       5.1                                     40        V        12.1      34       1.8                                     41        V        12.2      34       0.6                                     42        VI       11.8      32       4.3                                     43        VI       12.8      34       6.5                                     44        VI       12.0      34       6.0                                     45        VI       11.8      32       2.7                                     46        V        11.8      32       5.8                                     47        I        12.7      34       3.1                                     48        II       12.1      32       6.7                                     49        II       12.1      32       6.6                                     50        II       12.1      32       4.8                                     51        II       12.3      32       4.3                                     52        II       12.1      32       6.8                                     53        II       12.0      32       5.7                                     54        II       11.9      32       7.2                                     55        II       12.4      32       4.2                                     56        IV       12.3      32       7.3                                     57        II       12.1      32       4.9                                     58        II       11.8      34       7.3                                     59        IV       11.9      28       4.9                                     60        II       12.1      34       6.7                                     61        II       12.4      32       6.5                                     62        II       12.0      32       5.9                                     63        IV       11.9      34       7.4                                     64        IV       11.8      32       7.3                                     65        IV       11.5      26       5.4                                     66        IV       11.5      30       6.1                                     67        IV       11.4      30       5.2                                     68        VI       11.8      32       2.5                                     69        V        12.5      34       5.9                                     70        II       12.1      32       6.7                                     71        II       12.3      32       6.8                                     72        II       11.9      32       7.2                                     73        IV       11.7      32       7.2                                     74        II       12.4      32       4.7                                     75        II       12.0      30       4.7                                     76        IV       11.5      30       6.1                                     77        IV       11.9      32       6.0                                     78        IV       11.4      30       5.7                                     79        IV       11.7      30       5.2                                     80        IV       12.1      30       7.8                                     81        IV       12.0      32       7.6                                     82*       I                  Failed                                           83*       I                  Failed                                           84*       I                  Failed                                           85*       I        9.6       32       6.6                                     86*       I                  Failed                                           87*       I                  Failed                                           88*       III      11.1      34       2.0                                     89        I        11.8      28       2.2                                     90        III      11.9      24       3.6                                     91*       I                  Failed                                           92*       I                  Failed                                           93*       I                  Failed                                           94        III      12.2      32       5.8                                     95        VI       11.4      32       3.9                                     96        VI       11.8      32       6.1                                     97        VI       11.8      30       7.3                                     98        VI       11.3      32       6.0                                     99        V        12.5      32       5.9                                     ______________________________________                                    

EXAMPLE 101

About 8.0 g. of pyridinium dodecylbenzenesulfonate catalyst was added to792 g. of a polysiloxane-poly(oxyethylene-oxypropylene) block copolymerprepared according to conditions and procedure of Example 1 which hadbeen heated to 120° C. The catalyzed block copolymer was held at 120°C., aliquots were withdrawn at 1 hour intervals and filtered throughsodium bicarbonate. After five hours sufficient toluene was added togive a solution containing 60 percent by weight of thepolysiloxane-poly(oxyethylene-oxypropylene) block copolymer. After anadditional hour at 120° C. sodium bicarbonate was added, the toluene wasremoved by distillation and the residual sodium bicarbonate and saltsformed in neutralization were removed from the block copolymer byfiltration. The polyurethane foam stabilizing properties of the blockcopolymers so prepared, according to above defined Test III procedureare shown in Table 2 below.

                  TABLE 2                                                         ______________________________________                                        Time                Height    Cells   Air                                     After Addition                                                                            Foam    of Rise,  Per     Flow                                    of Catalyst Test    Inches    Inch    Rate                                    ______________________________________                                        Before treatment                                                                          III     12.3      34      7.0                                     1 Hour      III     11.9      34      6.3                                     2 Hours     III     11.2      32      5.9                                     3 Hours     III     11.0      32      5.9                                     4 Hours     III               Failed                                          5 Hours     III               Failed                                          1 Hour After                                                                  Addition of                                                                   Toluene     III     11.4      32      6.7                                     ______________________________________                                    

EXAMPLE 102

Polysiloxane-poly(oxyethylene-oxypropylene block copolymers producedaccording to the conditions and procedures of Examples 6, 63, 97 and 99along with a commercial hydrolyzable polysiloxane-polyoxyalkylene blockcopolymer (Goldschmidt BF-2270, a product of Th. Goldschmidt A.G.) wereevaluated as foam stabilizers for flexible polyether polyurethane foamin a foam formulation in which a range of tin catalyst concentrationswere used. The following foam formulation was employed.

                  FORMULATION                                                     ______________________________________                                        Material             Parts by Weight                                          ______________________________________                                        Polyol II            100                                                      Distilled Water      4.0                                                      Bis(2-dimethylaminoethyl)ether                                                                     0.1                                                      C Cl.sub.3 F         5.0                                                      TDI                  48.1                                                     Polysiloxane-polyoxyalkylene                                                  block copolymer      1.0                                                      Stannous Octoate     Varied as                                                                     shown in                                                                      TABLE 3                                                  ______________________________________                                    

The foams were produced by adding the polysiloxane-polyoxyalkylene blockcopolymer to Polyol II in a 1000 ml. container, mixing with a spatula,adding a mixture of water and the amine ether to the container, addingCCl₃ F to the container, mixing with a drill press for 15 seconds,adding the stannous octoate, mixing for 8 seconds with a drill pressadding the TDI, mixing with a drill press for 7 seconds, pouring into amold and curing for 15 minutes at 135° C. Prior to the cure thetemperature of the materials was maintained at no higher than 25° C. Thetest results are given in TABLE 3 below.

                  TABLE 3                                                         ______________________________________                                        Product Stannous     Height    Cells  Air                                     of      Octoate      of Rise,  per    Flow                                    Example (Parts by Wt.)                                                                             Inches    Inch   Rate                                    ______________________________________                                        63      0.15         7.5       30-35  8.2                                     63      0.20         7.9       30-35  6.8                                     63      0.25         7.6       34-40  6.1                                     63      0.30         8.2       35-40  4.8                                     63      0.325        8.3       35-40  3.8                                     BF-2270*                                                                              0.15         7.4       30-35  6.5                                     BF-2270*                                                                              0.20         8.2       30-35  6.1                                     BF-2270*                                                                              0.25         7.9       30-35  3.2                                     BF-2270*                                                                              0.30         8.1       35-40  3.0                                     BF-2270*                                                                              0.325        8.2       30-35  1.7                                     99      0.17         9.1       35-40  6.1                                     99      0.20         9.3       35-40  5.4                                     99      0.25         9.3       35-40  3.6                                     99      0.30         9.5       35-40  0.8                                      6*     0.17         9.2       35-40  2.4                                      6*     0.25         9.4       35-40  1.5                                      6*     0.30         Shrinkage and Voids                                      97      0.15         8.6       35-40  6.5                                     97      0.20         9.2       35-40  4.9                                     97      0.25         9.6       35-40  3.3                                     97      0.30         9.5       35-40  1.8                                     97      0.35         9.9       35-40  ˜0.1                              ______________________________________                                    

The above data demonstrates that better open foams can be achieved overa broader range of tin catalyst concentrations by employing as the foamstabilizer, the polysiloxane-polyoxyalkylene block copolymers of thisinvention rather than the block copolymers which are not of thisinvention.

Various modifications and variations of this invention will be obviousto a worker skilled in the art and it is to be understood that suchmodifications and variations are to be included within the purview ofthis application and the spirit and scope of the appended claims.

What is claimed is:
 1. A polyoxyalkylene polyether admixture consistingessentially of from about 20 to about 80 percent by weight of component(A) and from about 80 to about 20 percent by weight of component (B),said percentages being based on the total weight of components (A) and(B) present in the admixture, wherein component (A) represents lowmolecular weight polyoxyalkylene polyether, said polyether beingselected from the class consisting of (i) a polyoxyalkylene copolymerhaving an average molecular weight in the range of from about 800 toabout 2300 wherein about 20 to about 60 weight percent of theoxyalkylene groups of said copolymer are oxyethylene, the remainder ofthe oxyalkylene groups being oxypropylene, and (ii) a blend of at leasttwo polyoxyalkylene copolymers having different average molecularweights in the range of from about 500 to about 2900 and wherein about20 to about 60 weight percent of the oxyalkylene groups of thecopolymers in said blend are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene, with the proviso that said blendhas an average molecular weight in the range of from about 800 to about2300; and wherein component (B) represents high molecular weightpolyoxyalkylene polyether, said polyether being selected from the classconsisting of (i) a polyoxyalkylene copolymer having an averagemolecular weight in the range of from about 3400 to about 5500, whereinabout 20 to about 60 weight percent of the oxyalkylene groups of saidcopolymer are oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene, and (ii) a blend of at least two polyoxyalkylenecopolymers having different average molecular weights in the range offrom about 3000 to about 5500 and wherein about 20 to about 60 weightpercent of the oxyalkylene groups of the copolymers in said blend areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,with the proviso that said blend has an average molecular weight in therange from about 3400 to 5500, and wherein the polyoxyalkylenecopolymers of (A) and (B) contain terminal groups selected from theclass consisting of hydroxy and alkenyloxy at one end of the copolymerand terminal groups selected from the class consisting of alkoxy,aryloxy and aralkyloxy at the other end of the copolymer, with theproviso that when the copolymer contains a terminal alkenyloxy group atone end, the terminal group at the other end of the copolymer can alsobe acyloxy; with the added proviso that said admixture of (A) and (B)has an average molecular weight in the range of about 1600 to about2900.
 2. A polyoxyalkylene polyether admixture as defined in claim 1,wherein the polyoxyalkylene copolymers of (A) and (B) contain a hydroxyterminal group at one end of the copolymer and an alkoxy terminal groupat the other end of the copolymer.
 3. A polyoxyalkylene polyetheradmixture as defined in claim 1 wherein the polyoxyalkylene copolymer of(A) and (B) contain an alkenyloxy terminal group at one end of thecopolymer and an alkoxy terminal group at the other end of thecopolymer.
 4. A polyoxyalkylene polyether admixture as defined in claim1, wherein (A) represents a low molecular weight polyoxyalkylenecopolymer having an average molecular weight in the range of from about800 to about 2300; wherein (B) represents a high molecular weightpolyoxyalkylene copolymer having an average molecular weight in therange of from about 3400 to about 5500; and wherein the oxyalkylenegroups in said copolymers of (A) and (B) are present in a randomdistribution.
 5. A polyoxyalkylene polyether admixture as defined inclaim 4, wherein said admixture consists essentially of from about 25 toabout 50 percent by weight of (A), said low molecular weightpolyoxyalkylene copolymer having an average molecular weight in therange of from about 900 to about 1300, wherein about 30 to about 55weight percent of the oxyalkylene groups of said copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene;and from about 75 to about 50 percent by weight of (B), said highmolecular weight polyoxyalkylene copolymer having an average molecularweight in the range of from about 3800 to about 5000, wherein about 30to about 55 weight percent of the oxyalkylene groups of said copolymerare oxyethylene, the remainder of the oxyalkylene groups beingoxypropylene; and wherein said admixture of (A) and (B) has an averagemolecular weight in the range of about 2000 to about
 2400. 6. Apolyoxyalkylene polyether admixture as defined in claim 5, wherein theterminal group at one end of the copolymers of (A) and (B) is analkenyloxy group and the terminal group at the other end of thecopolymers of (A) and (B) is an alkoxy group.
 7. A polyoxyalkyleneadmixture as defined in claim 6, wherein the alkenyloxy group isallyloxy and wherein the alkoxy group is methoxy.
 8. A polyoxyalkylenepolyether admixture as defined in claim 1, wherein (A) represents ablend of at least two low molecular weight polyoxyalkylene copolymershaving different average molecular weights in the range of about 500 toabout 2900, with the proviso that said blend has an average molecularweight in the range of from about 800 to about 2300; wherein (B)represents a high molecular weight polyoxyalkylene copolymer having anaverage molecular weight in the range of from about 3400 to about 5500and wherein the oxyalkylene groups in said copolymers of (A) and (B) arepresent in a random distribution.
 9. A polyoxyalkylene polyetheradmixture as defined in claim 8, wherein said admixture consistsessentially of from about 30 to about 60 percent by weight of (A), atleast one of said low molecular weight polyoxyalkylene copolymers havingan average molecular weight in the range of from about 900 to about 1300and at least one of said low molecular weight polyoxyalkylene copolymershaving an average molecular weight in the range of from about 1700 toabout 2900 and wherein about 30 to about 55 weight percent of theoxyalkylene groups of the copolymers in said blend of (A) areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene,with the proviso that said blend of (A) has an average molecular weightin the range of from about 1100 to about 1900; and from about 70 toabout 40 percent by weight of (B), said high molecular weightpolyoxyalkylene copolymer having an average molecular weight in therange of from about 3800 to about 5000 and wherein about 30 to about 55weight percent of the oxyalkylene groups of said copolymer areoxyethylene, the remainder of the oxyalkylene groups being oxypropylene.10. A polyoxyalkylene polyether admixture as defined in claim 9 whereinthe polyoxyalkylene copolymers of (A) and (B) contain terminal groupsselected from the class consisting of hydroxy and allyloxy at one end ofthe copolymer and a terminal alkoxy group at the other end of thecopolymer.
 11. A polyoxyalkylene polyether admixture as defined in claim1, wherein (A) represents a low molecular weight polyoxyalkylenecopolymer having an average molecular weight in the range of from about800 to about 2300; wherein (B) represents a blend of at least two highmolecular weight polyoxyalkylene copolymers having differnt averagemolecular weights in the range of about 3000 to about 5500, with theproviso that said blend has an average molecular weight in the range offrom about 3400 to about 5500; and wherein the oxyalkylene groups insaid copolymers of (A) and (B) are present in a random distribution. 12.A polyoxyalkylene polyether admixture as defined in claim 11, whereinsaid admixture consists essentially of from about 30 to about 60 percentby weight of (A), said low molecular weight polyoxyalkylene copolymerhaving an average molecular weight in the range of about 900 to about1300 and wherein about 30 to about 55 weight percent of the oxyalkylenegroups of said copolymer are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene; and from about 70 to about 40percent by weight of (B), at least one of said high molecular weightpolyoxyalkylene copolymers having an average molecular weight in therange of from about 3000 to about 3400 and at least one of said highmolecular weight polyoxyalkylene copolymers having an average molecularweight in the range of from about 3800 to about 5000 and wherein about30 to about 55 weight percent of the oxyalkylene groups of thecopolymers in said blend of (B) are oxyethylene, the remainder of theoxyalkylene groups being oxypropylene, with the proviso that said blendof (B) has an average molecular weight in the range of from about 3400to about 5000; and with the added proviso that said admixture of (A) and(B) has an average molecular weight in the range of from about 1600 toabout
 2600. 13. A polyoxyalkylene polyether admixture as defined inclaim 12, wherein the polyoxyalkylene copolymers of (A) and (B) containan allyloxy terminal group at one end of the copolymer and a terminaln-butoxy group at the other end of the copolymer.
 14. A polyoxyalkylenepolyether admixture as defined in claim 12, wherein the polyoxyalkylenecopolymers of (A) and (B) contain a hydroxy terminal group at one end ofthe copolymer and a terminal n-butoxy group at the other end of thecopolymer.
 15. A polyoxyalkylene polyether admixture as defined in claim1, wherein (A) represents a blend of at least two molecular weightpolyoxyalkylene copolymers having different average molecular weights inthe range of about 500 to about 2900, with the proviso that said blendhas an average molecular weight in the range of from about 800 to about2300; and wherein (B) represents a blend of at least two high molecularweight polyoxyalkylene copolymers having different average molecularweights in the range of about 3000 to about 5500, with the proviso thatsaid blend has an average molecular weight in the range of from about3400 to about 5500; and wherein the oxyalkylene groups in saidcopolymers of (A) and (B) are present in a random distribution.